MediaSession play/pause events not propagated to LeanbackPlayerAdapter

[TheBeastLT]

ExoPlayer Version

2.18.0

Devices that reproduce the issue

Any Android TV

Devices that do not reproduce the issue

No response

Reproducible in the demo app?

Yes

Reproduction steps

Connect player with a MediaSession and try to play/pause the video using mobile.

Expected result

When clicking play/pause the controls overlay should be triggered and their state updated.

It seems that the LeanbackPlayerAdapter listens to onPlaybackStateChanged player events, but play/pause action called from MediaSessionConnector. directly on a Player instance triggers only onPlayWhenReadyChanged event, which is not handled in the LeanbackPlayerAdapter.
By using ForwadingPlayer when setting player for the MediaSessionConnector. you can workaround this issue:

mediaSessionConnector.setPlayer(object : ForwardingPlayer(player) {
    override fun play() {
        playerAdapter.play()
    }

    override fun pause() {
        playerAdapter.pause()
    }

    override fun stop() {
        playerAdapter.pause()
    }
})

Actual result

Controls overlay is not triggered and play/pause action stays in previous incorrect state.

Media

Not applicable

Bug Report

• You will email the zip file produced by adb bugreport to dev.exoplayer@gmail.com after filing this issue.

[christosts]

Thank you for reporting this. We submitted a fix (this issue will be updated once the commit is pushed the dev-v2 branch) which will be included in the next release (2.18.1 or 2.19.0, which ever comes first).