A session may not notify its release back to the controller
when the controller is connecting while the session is releasing.
Here are issues in detail:
- MediaSession doesn't respond to controller's connection
request when it's released.
- MediaSession discards incoming connection requests when it's
released. The requests are only kept in the application
looper, but the looper is cleared when the session is
released.
This CL fixes the above issues, and fixes some flaky tests.
PiperOrigin-RevId: 419756158
bb81c4969d