Handle Android/OpenXR lifecycle correctly

[kanerogers]

Description

Having some issues getting Hotham to behave well with the Oculus runtime. For example, pressing then results in:

09-15 12:51:12.728  8773  8773 E ActivityThread: Activity android.app.NativeActivity has leaked IntentReceiver com.oculus.vrapi.UserSwitchedReceiver@5b373cb that was originally registered here. Are you missing a call to unregisterReceiver()?
09-15 12:51:12.728  8773  8773 E ActivityThread: android.app.IntentReceiverLeaked: Activity android.app.NativeActivity has leaked IntentReceiver com.oculus.vrapi.UserSwitchedReceiver@5b373cb that was originally registered here. Are you missing a call to unregisterReceiver()?

Also noted is the sequence of Android/OpenXR events:

09-15 12:51:12.988  8773  8797 I RustStdoutStderr: [HOTHAM_ANDROID] Received event WindowDestroyed
09-15 12:51:12.988  8773  8797 I RustStdoutStderr: [HOTHAM_POLL_EVENT] Received some other event
09-15 12:51:14.001  8773  8797 I RustStdoutStderr: [HOTHAM_ANDROID] Received event Stop
09-15 12:51:15.040  8773  8797 I RustStdoutStderr: [HOTHAM_ANDROID] Received event InputQueueDestroyed
09-15 12:51:16.067  8773  8797 I RustStdoutStderr: [HOTHAM_ANDROID] Received event Destroy
09-15 12:51:17.112  8773  8798 I OpenXR_Actions: ------------ xrDestroyAction -----------
09-15 12:51:17.112  8773  8798 I OpenXR_Actions: ------------ xrDestroyAction -----------
09-15 12:51:17.112  8773  8798 I OpenXR_Actions: ------------ xrDestroyActionSet --------
09-15 12:51:17.112  8773  8798 I OpenXR  : ------------ xrDestroySession [start] -----------
09-15 12:51:17.113  8773  8798 D SystemActivitiesReceiver: Unregistering Oculus System Activity receiver
09-15 12:51:17.113  8773  8798 I VulkanLoader: ovrVulkanLoader::Unload
09-15 12:51:17.113  8773  8798 I AudioCapture: AudioCapture::Shutdown
09-15 12:51:17.114  8773  8798 I AudioCapture: AudioCapture::StopAudioConsumerThread
09-15 12:51:17.114  8773  8798 I AudioCapture: AudioCapture::StopAudioConsumerThread COMPLETE

We might be handling things in the wrong order - we may have to respond to OpenXR before we just stop the app - even if we receive an Android Stop event.

TODO

• Research correct behaviour of Android lifecycle
• Research correct behaviour of OpenXR lifecycle
• Implement correctly

[kanerogers]

Note, we need to call ndk_glue::native_activity().finish() when exiting gracefully