stagefright: MetadataRetriever API to specify mime and color format

- Allow setDataSource() to specify mime. In case of HEIF decoding
  request from skia, we don't want to sniff any other format other
  than mp4.

- Allow getFrameAtTime() to specify dst color format.

bug: 64077740

Test: cts-tradefed run cts-dev --module CtsMediaTestCases --compatibility:module-arg CtsMediaTestCases:include-annotation:android.platform.test.annotations.RequiresDevice

Change-Id: I471f41c28a2252417c4b3331dcfd4bd00a24408a