Fixing Cobalt APK JNI initialization (#4359)

- Move JNI state variables into a standalone dynamic library to ensure
all callers obtain consistent, shared state.

- Disable POSIX emulation functions, they run into initialization order
conflicts where JNI state isn't available when functions like `close`
are already called.

- Disable problematic extensions that interact early with JNI

- Fix initialization order. Chromium library loader (
LibraryLoader.ensureInitialized ) needs to run and load all dynamic
libraries and initialize its JNI environment, before Starboard bridge
loads. It also calls `JNI_OnLoad` in `cobalt_library_loader.cc` and
passes it a VM pointer.

- Restore StarboardBridge native JNI initialization, start the Starboard
thread, and enable related minimal modules, including AudioManager and
VideoSurfaceView

- Ensure JNI_VERSION matches with what Chromium default uses (
JNI_VERSION_1_6 is only used for Cronet, but not elsewhere ).

- Ensure initial deeplink variable is never null to prevent crashing
early init, use an empty string instead.

b/376348543

cobalt/android/BUILD.gn

@@ -87,8 +87,7 @@ android_library("cobalt_apk_java") {
     "apk/app/src/main/java/dev/cobalt/coat/VolumeStateReceiver.java",
     "apk/app/src/main/java/dev/cobalt/libraries/services/clientloginfo/ClientLogInfo.java",
     "apk/app/src/main/java/dev/cobalt/libraries/services/clientloginfo/ClientLogInfoModule.java",
-
-    # "apk/app/src/main/java/dev/cobalt/media/AudioOutputManager.java",
+    "apk/app/src/main/java/dev/cobalt/media/AudioOutputManager.java",
     "apk/app/src/main/java/dev/cobalt/media/AudioTrackBridge.java",
     "apk/app/src/main/java/dev/cobalt/media/Log.java",
     "apk/app/src/main/java/dev/cobalt/media/MediaCodecBridge.java",
@@ -169,6 +168,7 @@ shared_library("libcobalt_content_shell_content_view") {
     "//content/shell/android:content_shell_jni_headers",
     "//media",
     "//skia",
+    "//starboard/android/shared:starboard_jni_state",
   ]
 
   # Explicit dependency required for JNI registration to be able to

cobalt/android/apk/apk_sources.gni

@@ -41,6 +41,7 @@ apk_sources = [
   "//starboard/android/apk/app/src/main/java/dev/cobalt/libraries/services/clientloginfo/ClientLogInfo.java",
   "//starboard/android/apk/app/src/main/java/dev/cobalt/libraries/services/clientloginfo/ClientLogInfoModule.java",
   "//starboard/android/apk/app/src/main/java/dev/cobalt/media/AudioOutputManager.java",
+  "//starboard/android/apk/app/src/main/java/dev/cobalt/media/AudioOutputManager.java",
   "//starboard/android/apk/app/src/main/java/dev/cobalt/media/AudioTrackBridge.java",
   "//starboard/android/apk/app/src/main/java/dev/cobalt/media/Log.java",
   "//starboard/android/apk/app/src/main/java/dev/cobalt/media/MediaCodecBridge.java",