[native] Secure store - add android part

Summary: Android implementation for our code of `expo-secure-store`

Test Plan:
I used the code below to test these changes:
```
static bool randInit = false;
  {
    if (randInit) {
      Logger::log("here init rand");
      randInit = true;
      srand((unsigned)time(0));
    }
    auto generateRandomString = [](size_t size) {
      std::string str;
      for (size_t i = 0; i < size; ++i) {
        str += 'A' + rand() % 24;
      }
      return str;
    };

    Logger::log("here test secure store #0");
    SecureStore secureStore;
    std::string key = generateRandomString(20);
    Logger::log("here test secure store #1(write): " + key);
    secureStore.set("pickleKey", key);
    std::string result = secureStore.get("pickleKey");
    Logger::log("here test secure store #2 (read): " + result);
  }
```

Reviewers: palys-swm, ashoat

Reviewed By: palys-swm, ashoat

Subscribers: ashoat, palys-swm, Adrian, atul

Differential Revision: https://phabricator.ashoat.com/D1823

native/android/app/src/cpp/CommSecureStore.cpp

@@ -0,0 +1,39 @@
+#include "CommSecureStore.h"
+#include <fbjni/fbjni.h>
+
+using namespace facebook::jni;
+
+class CommSecureStoreJavaClass : public JavaClass<CommSecureStoreJavaClass> {
+public:
+  static auto constexpr kJavaDescriptor =
+      "Lapp/comm/android/fbjni/CommSecureStore;";
+
+  static void set(std::string key, std::string value) {
+    static const auto cls = javaClassStatic();
+    static auto method =
+        cls->getStaticMethod<void(std::string, std::string)>("set");
+    method(cls, key, value);
+  }
+
+  static folly::Optional<std::string> get(std::string key) {
+    static const auto cls = javaClassStatic();
+    static auto method =
+        cls->getStaticMethod<facebook::jni::JString(std::string)>("get");
+    const auto result = method(cls, key);
+    return (result) ? folly::Optional<std::string>(result->toStdString())
+                    : folly::none;
+  }
+};
+
+namespace comm {
+
+void CommSecureStore::set(const std::string key, const std::string value)
+    const {
+  CommSecureStoreJavaClass::set(key, value);
+}
+
+folly::Optional<std::string> CommSecureStore::get(const std::string key) const {
+  return CommSecureStoreJavaClass::get(key);
+}
+
+} // namespace comm

native/android/app/src/main/java/app/comm/android/CommCoreJSIModulePackage.java

@@ -1,15 +1,16 @@
 package app.comm.android;
 
-import com.facebook.react.bridge.JSIModulePackage;
 import com.facebook.react.bridge.JSIModuleSpec;
 import com.facebook.react.bridge.JavaScriptContextHolder;
 import com.facebook.react.bridge.ReactApplicationContext;
 import java.util.Collections;
 import java.util.List;
 import app.comm.android.fbjni.CommHybrid;
+
 import com.swmansion.reanimated.ReanimatedJSIModulePackage;
 
 public class CommCoreJSIModulePackage extends ReanimatedJSIModulePackage {
+
   @Override
   public List<JSIModuleSpec> getJSIModules(
     ReactApplicationContext reactApplicationContext,

native/android/app/src/main/java/app/comm/android/MainApplication.java

@@ -1,5 +1,6 @@
 package app.comm.android;
 
+import app.comm.android.fbjni.CommSecureStore;
 import app.comm.android.generated.BasePackageList;
 
 import androidx.multidex.MultiDexApplication;
@@ -9,19 +10,16 @@
 
 import org.unimodules.adapters.react.ModuleRegistryAdapter;
 import org.unimodules.adapters.react.ReactModuleRegistryProvider;
-import org.unimodules.core.interfaces.SingletonModule;
 
 import com.facebook.react.PackageList;
-import com.facebook.hermes.reactexecutor.HermesExecutorFactory;
-import com.facebook.react.bridge.JavaScriptExecutorFactory;
 import com.facebook.react.bridge.JSIModulePackage;
 import com.facebook.react.ReactApplication;
 import com.facebook.react.ReactInstanceManager;
 import com.facebook.react.ReactNativeHost;
 import com.facebook.react.ReactPackage;
-import com.facebook.react.shell.MainReactPackage;
 import com.facebook.soloader.SoLoader;
 
+import expo.modules.securestore.SecureStoreModule;
 import io.invertase.firebase.messaging.RNFirebaseMessagingPackage;
 import io.invertase.firebase.notifications.RNFirebaseNotificationsPackage;
 
@@ -70,6 +68,10 @@ protected String getJSMainModuleName() {
 
     @Override
     protected JSIModulePackage getJSIModulePackage() {
+      SecureStoreModule secureStoreModule = (SecureStoreModule) 
+        mModuleRegistryProvider.get(getApplicationContext())
+        .getExportedModuleOfClass(SecureStoreModule.class);
+      CommSecureStore.getInstance().initialize(secureStoreModule);
       return new CommCoreJSIModulePackage();
     }
   };

native/android/app/src/main/java/app/comm/android/fbjni/CommSecureStore.java

@@ -0,0 +1,86 @@
+package app.comm.android.fbjni;
+
+import org.unimodules.core.Promise;
+import org.unimodules.core.arguments.MapArguments;
+import org.unimodules.core.arguments.ReadableArguments;
+
+import expo.modules.securestore.SecureStoreModule;
+
+public class CommSecureStore {
+
+  private static final CommSecureStore instance = new CommSecureStore();
+  private SecureStoreModule secureStoreModule = null;
+  private final ReadableArguments readableArguments;
+
+  private CommSecureStore() {
+    this.readableArguments = new MapArguments();
+  }
+
+  public static CommSecureStore getInstance() {
+    return CommSecureStore.instance;
+  }
+
+  public void initialize(SecureStoreModule secureStoreModule) {
+    this.secureStoreModule = secureStoreModule;
+  }
+
+  private void checkModule() {
+    if (this.secureStoreModule == null) {
+      throw new RuntimeException(
+        "secure store module has not been initialized"
+      );
+    }
+  }
+
+  private void internalSet(String key, String value) {
+    this.checkModule();
+    Promise promise = new Promise() {
+      @Override
+      public void resolve(Object value) {}
+
+      @Override
+      public void reject(String code, String message, Throwable e) {
+        throw new RuntimeException("secure store set error: " + message);
+      }
+    };
+    this.secureStoreModule.setValueWithKeyAsync(
+      value,
+      key,
+      this.readableArguments,
+      promise
+    );
+  }
+
+  private String internalGet(String key) {
+    this.checkModule();
+    final String[] result = {null};
+
+    Promise promise = new Promise() {
+      @Override
+      public void resolve(Object value) {
+        result[0] = (String)value;
+      }
+
+      @Override
+      public void reject(String code, String message, Throwable e) {
+        throw new RuntimeException("secure store get error: " + message);
+      }
+    };
+    // The following call will resolve the promise before it returns
+    this.secureStoreModule.getValueWithKeyAsync(
+      key,
+      this.readableArguments,
+      promise
+    );
+
+    return result[0];
+  }
+
+  public static void set(String key, String value) {
+    getInstance().internalSet(key, value);
+  }
+
+  public static String get(String key) {
+    return getInstance().internalGet(key);
+  }
+}