Create a new NetplaySession each time we try to join a netplay game. Hold onto it in NetplayManager so its available to the different activities that need to access it. Close the session when backing out of the netplay UI. Some guardrails in case things go out of sync: creating a session closes the old one if it is still around for some reason, finalizer in NetplaySession to release native resources if not closed explicitly for some reason. Profiling done to ensure all kotlin and native objects are successfully cleared / garbage collected.

For some reason, NativeLibrary.kt calling Log for the alert message text
makes Dolphin die with a JNI error. Supposedly the jstring passed to the
logging function is invalid. I don't understand why, because the dialog
that we show right afterwards is able to read the string just fine. The
error happens even if I pass the string directly to Log without
prepending any extra text.

There's no real downside to having the logging in C++ instead of Kotlin,
so let's move it to C++ to avoid the JNI error.

Follow-up to 068947e. HostThreadLock no longer serves a purpose.

This keeps the logic encapsulated inside GCAdapter.cpp so callers don't
have to think about it.

Android: Add Reset Dolphin Settings functionality

Android: Use the shared HTTP analytics backend