I succeeded in playing the game project on android through quick launching.
But, I can’t start my project on the android smartphone by shipping package. It shows splash screen with the unreal logo first and then shuts down.
dalvik.system.InMemoryDexClassLoader[DexPathList[[dex file "InMemoryDexFile[cookie=[0, -5476376607604504976]]"],nativeLibraryDirectories=[/system/lib64, /system_ext/lib64]]] couldn't find "libUnreal.so"
This message (android studio logcat) is thrown always when I process my project. I know that libUnreal.so file is my C++ code. So I expect that my game can’t find libUnreal.so for processing it and shut down.
I packaged my project successfully (UE 5.2) and downloaded it by [MyProject]-Android-Shipping-arm64.bat file (Galaxy S21+).
If I can include libUnreal.so when downloading the app to my phone, I think the problem will be solved. So, how can I do this?
I suffered from this for about a month… please help me 
I found that libUnreal.so file is already included in apk file.
But I still have failed to start my game.
I also attempted to install by .aab file through bundle tool, and failed.
I solved my problem. In other words, that throwing was just nothing. I thought I attracted to red letters on the logcat.
I leave this reply for fool man just like me (I spent about two week for this problem). If you are packaging for Android, it maybe helps you do this well.
First, couldn't find "libUnreal.so" message is thrown always regardless of packaging or launching methods. Just never mind.
Second, GVRTransition2DActivity.getActivity() failed. Trying to get GameActivity. message is thrown always too.
I looked around some unreal java source code, it is for Daydream App (Currently deprecated). Check if your app is Daydream app, then return available GameActivity if not. So this is no problem.
Third, most of the issues are occurred in your code maybe. Package process doesn’t catch all of the errors in your code. Check them by Android Studio Logcat.
Last, if you really don’t know what is wrong, just try removing all of the automatically generated files like immediate, saved, binaries, DerivedDataCache and etc. Then execute Generate Visual Studio files by uproject file (if you use this ide) and completely rebuild your project. finally, execute Cook Content. And then try again.
I hope this helps you.