[Android] Add onUserLeaveHint support to ReactActivityDelegate

[behenate]

Summary:

This PR adds onUserLeaveHint support into the ReactActivityDelegate. It allows modules to receive an event every time user moves the app into the background. This is slightly different than onPause - it's called only when the user intentionally moves the app into the background, e.g. when receiving a call onPause should be called but onUserLeaveHint shouldn't.

This feature is especially useful for libraries implementing features like Picture in Picture (PiP), where using onUserLeaveHint is the recommended way of auto-entering PiP for android < 12.

This is a re-submission of #42741. The problematic assert has been changed to an if - it's not a problem if onUserLeaveHint is received from an activity different to the current one, but in that case we shouldn't emit the event.

Changelog:

[ANDROID] [ADDED] - Added onUserLeaveHint support into ReactActivityDelegate

Test Plan:

Tested in the rn-tester app - callbacks are correctly called on both old and new architecture.

[analysis-bot]

Platform	Engine	Arch	Size (bytes)	Diff
android	hermes	arm64-v8a	18,073,866	-9
android	hermes	armeabi-v7a	n/a	--
android	hermes	x86	n/a	--
android	hermes	x86_64	n/a	--
android	jsc	arm64-v8a	21,440,610	-11
android	jsc	armeabi-v7a	n/a	--
android	jsc	x86	n/a	--
android	jsc	x86_64	n/a	--

Base commit: 6c50418
Branch: main

[facebook-github-bot]

@cortinico has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator.

[facebook-github-bot]

@cortinico merged this pull request in 3cf6c64.

[facebook-github-bot]

This pull request has been reverted by f2f62cd.

[cortinico]

@behenate sadly this had to be reverted once more due to a crash on one of our internal products. I'll get back to you on Monday with more details and we'll see what are the next steps

[behenate]

@cortinico Interesting, I'm not sure what could be causing a crash in this code as it's pretty straightforward. Waiting for more info!

[cortinico]

@behenate so the app gets stuck on the loading screen with this stacktrace:

E  Handling exception for crash
java.lang.AssertionError
	at com.facebook.infer.annotation.Assertions.assertCondition(Assertions.java:82)
	at com.facebook.react.ReactInstanceManager.onUserLeaveHint(ReactInstanceManager.java:596)
	at com.facebook.react.ReactDelegate.onUserLeaveHint(ReactDelegate.java:105)
	at com.facebook.react.ReactActivityDelegate.onUserLeaveHint(ReactActivityDelegate.java:129)
	at com.facebook.react.ReactActivity.onUserLeaveHint(ReactActivity.java:111)
	at android.app.Activity.performUserLeaving(Activity.java:9167)
	at android.app.Instrumentation.callActivityOnUserLeaving(Instrumentation.java:1667)
	at android.app.ActivityThread.performUserLeavingActivity(ActivityThread.java:5693)
	at android.app.ActivityThread.handlePauseActivity(ActivityThread.java:5673)
	at android.app.servertransaction.PauseActivityItem.execute(PauseActivityItem.java:48)
	at android.app.servertransaction.ActivityTransactionItem.execute(ActivityTransactionItem.java:45)
	at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:180)
	at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:98)
	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2685)
	at android.os.Handler.dispatchMessage(Handler.java:106)
	at android.os.Looper.loopOnce(Looper.java:230)
	at android.os.Looper.loop(Looper.java:319)
	at android.app.ActivityThread.main(ActivityThread.java:8893)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:608)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1103)

[cortinico]

I'm unsure why onUserLeaveHint gets called when the app starts, but that's probably fine to don't assert around mRequireActivity and just go with:

      UiThreadUtil.assertOnUiThread();

      ReactContext currentContext = getCurrentReactContext();
      if (currentContext != null) {
        currentContext.onUserLeaveHint(activity);
      }

[behenate]

@cortinico I'm also not sure why onUserLeaveHint is called this early in the app, but it should be safe to ignore it. I will make another PR tomorrow. Hopefully third time's the charm 🙃

[cortinico]

@cortinico I'm also not sure why onUserLeaveHint is called this early in the app, but it should be safe to ignore it. I will make another PR tomorrow. Hopefully third time's the charm 🙃

Yup I also have repros instruction to verify if the app still crashes so we can see if all is green

[cortinico]

Sadly we have to revert this once more as it's causing a couple of internal apps to fail. Here the stacktrace:

#43642