Fix sample issues (#1716)

Author: samtstern

app/src/main/java/com/firebase/uidemo/auth/AuthUiActivity.java

@@ -185,6 +185,7 @@ public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
                     mUseEmailLinkProvider.setChecked(false);
                     mUsePhoneProvider.setChecked(false);
                     mUseAnonymousProvider.setChecked(false);
+                    mUseMicrosoftProvider.setChecked(false);
                     mUseYahooProvider.setChecked(false);
                     mUseAppleProvider.setChecked(false);
                 }

app/src/main/java/com/firebase/uidemo/util/ConfigurationUtils.java

@@ -69,6 +69,7 @@ public static List<AuthUI.IdpConfig> getConfiguredProviders(@NonNull Context con
         providers.add(new AuthUI.IdpConfig.PhoneBuilder().build());
         providers.add(new AuthUI.IdpConfig.MicrosoftBuilder().build());
         providers.add(new AuthUI.IdpConfig.YahooBuilder().build());
+        providers.add(new AuthUI.IdpConfig.AppleBuilder().build());
 
         return providers;
     }