Add support for RTSP AMR-NB/WB

[ManishaJajoo]

Added AMR-NB/WB RTP packet reader and added support for AMR-NB/WB
playback through RTSP

Change-Id: I0a975fa1e1aa8450bda1c828599a523ba796bc48

[claincly]

Interesting. RTP_MEDIA_AMR (which is "AMR"), corresponds to MIME type AUDIO_AMR_NB ("audio/3gpp") and not to AUDIO_AMR ("audio/amr")?

Do you know what would happen if you to map RTP_MEDIA_AMR to MimeTypes.AUDIO_AMR? Would the decoder work?

I skimmed through rfc4867 and I see that both AMR and AMR_WB can be stored in 3gpp files so I'd be tempted to see what happens when AMR_WB is also mapped to audio/3gpp.

[ManishaJajoo]

Upon setting the mimeType as AUDIO_AMR, the player fails in selectTracks. The reason for this failure is: AUDIO_AMR is treated as an unsupported mime type and therefore result.second is set to null here:
https://github.com/androidx/media/blob/main/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/trackselection/MappingTrackSelector.java#L422

Regarding the second change, i.e. mapping AMR_WB to audio/3gpp, since AUDIO_AMR_NB creates an AMR_NB decoder and AUDIO_AMR_WB creates AMR_WB decoder we see the following playback error:
MediaCodecDecoderException: Decoder failed: c2.android.amrnb.decoder

[claincly]

Merged internally. The issue will be marked as merged automatically when we do a push. Thanks for the contribution!