Merge "CCodecBufferChannel: add null checks" am: 324ee07643 am: fece72c946 am: 4d31beaed8

Original change: https://android-review.googlesource.com/c/platform/frameworks/av/+/1688971

Change-Id: I969f0a4046c82d9692596e9b2e587b66e1d373fc