media, non-mainline: Add basic AVIF decoding support

This CL contains files that are not part of mainline.

Parse the AVIF boxes and pass the data along to a compatible AV1
decoder (similar to how HEIC frames are passed to the HEVC
decoder).

Test: BitmapFactory.decodeByteArray() is now able to decode valid AVIF images.
Test: HEIF related CTS tests still pass.

CTS tests to come in a different CL.

Bug: 141654151
Change-Id: I4b84ae825232bb34f357725247a4531b87b3e029