MediaCodec: LinearBlock API for optional crypto

Split setter for LinearBlock in QueueRequest between:
- setLinearBlock for unencrypted streams
- setEncryptedLinearBlock with non-null crypto info

Bug: 149487982
Test: atest CtsMediaTestCases -- --module-arg CtsMediaTestCases:size:small
Change-Id: I7d147b3963febeb431b268262343c782f2c1e3e9