VideoFramePool: implement asynchronous frame fetching

This CL adds asynchronous frame fetching to VideoFramePool that relies
on new API introduced in Codec 2.0. When a buffer is not available the
new version of fetchGraphicBlock returns a C2_BLOCKING together fence
that will be signaled once the call should be retried.

Bug: 268301611
Bug: 268305422
Bug: 270329448
Bug: 238710012
Bug: 238390060
Bug: 270331759
Bug: 238709912
Test: CtsMediaCodecTestCases
Test: CtsMediaDecoderTestCases
Test: CtsMediaV2TestCases
Test: GtsExoPlayerTestCases com.google.android.exoplayer.gts.CommonEncryptionDrmTest#cencSchemeTypeV*
Change-Id: Id470113e2037ec2c69ed1ccbf2fe15a4facf80ce
(cherry picked from commit cb4034b1)