Move MediaBufferXXX from foundation to libmediaextractor

Removed MediaBufferBase in favor of MediaBufferHolder
which contains a MediaBuffer inside. Instead of set/getMediaBufferBase,
now it set/finds MediaBufferHolder in ABuffer->meta().

Test: build. pass MediaPlayerDrmTest and EncodeDecodeTest.
Bug: 67908542
Change-Id: Icb4f7ac350a7876f5e4596bae8be2a9e95956c2f