MediaCodec: address API review

- New exception for APIs that are incompatible with the new mode
- Better messages with exceptions
- QueueRequest API/documentation rework as per suggestion

Bug: 149487982
Test: atest CtsMediaTestCases:MediaCodecBlockModelTest
Change-Id: I48be448876c200208bb814e91b920c76d09a3b9e
2 files changed