SDK / exoplayer

The correct order of initializing the MediaCodec should be (as per
documentation
https://developer.android.com/reference/android/media/MediaCodec#initialization)

"create -> setCallback -> configure -> start"

but the MediaCodecRenderer currently does

"create -> configure -> setCallback -> start"

MediaCodec implementations did not complain about this so far, but the
wrong sequence does not work with the MediaCodec in block mode (new mode
in Android R) and also the ShadowMediaCodec won't operate in
asynchronous mode otherwise. To initialize the MediaCodec in the correct
order, this commit adds configure() in the MediaCodecAdapter so the
MediaCodecRenderer can do:

adapter.configure(); // sets the callback and then configures the codec
adapter.start();     // starts the codec

PiperOrigin-RevId: 316127680