AV1 Encoder: Fix 10bit encoding

This CL adds proper handling of 10bit input data. For now the only
10-bit input supported is P010.

Fixes: 256115786,255277757,253491266,249143037
Bug: 252836071

Test: atest CodecEncoderSurfaceTest

Change-Id: Id74efbc47bd0cc81895ce6d40a939efc19ec9794