While investigating a different test failure on a pending change I
noticed that sometimes the "testAddSessions_removedWhenClose" session
was being released before it could be fully connected - and this
results in a failure like:
```
expected not to contain: androidx.media3.session.MediaSession@50a9ef1
but was : [androidx.media3.session.MediaSession@50a9ef1, androidx.media3.session.MediaSession@3a6bac]
at androidx.media3.session.MediaSessionServiceTest.addSessions_removedWhenReleased(MediaSessionServiceTest.java:376)
```
It also shows up in the logs like:
```
MediaController future failed (so we couldn't release it)
...
Caused by: java.lang.SecurityException: Session rejected the connection request.
```
Adding some debug logging revealed that the `session.release` call
posted to the test thread was happening before the call to
`MediaSessionStub.connect` on the main thread (this is triggered deep
in prod media3 session logic).
PiperOrigin-RevId: 563431265
06f5324665