Add buffer provider that can adjust channels.

1. Add adjust channels buffer provider, which will expand or contract
sample data from one interleaved channel format to another. Expanded
channels are filled with zeros and put at the end of each frames.
Contracted channels are omitted from the end of each audio frame.

2. Add adjust channels non destructive buffer provider, which could
expand or contract sample data from one interleaved channel format to
another while not destructing the buffer. Extra expanded channels are
interleaved in from the end of the input buffer. Contracted channels are
copied to the end of the output buffer. Contracted channels could be
written to an output buffer with certain audio format.

Test: Manually
Bug: 111454766
Change-Id: I3f963307e73b3f7aa662d4127f78f0c61ac84510
4 files changed