QCamera: Add buf_index into stream_request definition.

Associating capture request with buffer indices of the
corresponding streams allows for better accountability
in the camera back-end.

Bug: 29314988
Ack-by: Mansoor Aftab
CRs-Fixed: 991191
Change-Id: Ie146205a6395ddcee112fde80aa00a37177c9ed9
2 files changed