Some final synchronized block cleanup (#4528)

Author: lfkellogg

firebase-appdistribution/src/main/java/com/google/firebase/appdistribution/impl/AabUpdater.java

@@ -160,11 +160,7 @@ private void openRedirectUrlInPlay(String redirectUrl, Activity hostActivity) {
     updateIntent.setData(Uri.parse(redirectUrl));
     updateIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
     LogWrapper.v(TAG, "Redirecting to play");
-
-    // Launch the intent before the synchronized block to avoid failing to update in the rare
-    // scenario where the activity moves to the background while we're awaiting the lock.
     hostActivity.startActivity(updateIntent);
-
     updateTaskCache.setProgress(
         UpdateProgressImpl.builder()
             .setApkBytesDownloaded(-1)

firebase-appdistribution/src/main/java/com/google/firebase/appdistribution/impl/FirebaseAppDistributionImpl.java

@@ -254,7 +254,7 @@ public void signOutTester() {
   }
 
   @Override
-  public synchronized Task<AppDistributionRelease> checkForNewRelease() {
+  public Task<AppDistributionRelease> checkForNewRelease() {
     return checkForNewReleaseTaskCache.getOrCreateTask(
         () ->
             assertTesterIsSignedIn()