Add onRemoveTrack for Android.

[cloudwebrtc]

fix livekit/client-sdk-android#17 (comment)
and flutter-webrtc/flutter-webrtc#746 (comment)

[davidzhao]

should we just upstream a later version of webrtc? The method exists in later versions of the repo. It seems that'd be more reliable versus integrating a patch.

[cloudwebrtc]

should we just upstream a later version of webrtc? The method exists in later versions of the repo. It seems that'd be more reliable versus integrating a patch.

https://webrtc.googlesource.com/src/+/ffbfba979f9d48176c7ed5dcc60b6a8076303b71
@davidzhao This makes sense, I will re-push the patch

[cloudwebrtc]

@davidzhao I temporarily updated the patch, we can try to fetch upstream. so that the main branch can be upgraded to a higher version.

[davidzhao]

sounds like a plan!

[cloudwebrtc]

I have synced the three major versions to the branches

M93 https://github.com/webrtc-sdk/webrtc/pull/new/branch-heads/4577
M94 https://github.com/webrtc-sdk/webrtc/pull/new/branch-heads/4606
M95 https://github.com/webrtc-sdk/webrtc/pull/new/branch-heads/4638