mediav2 CTS: encoder validation tests

Added audio encoder validation tests for all mandatory codec
requirements of android cdd. The encoded output is validated for
timestamps, duration, channel count, samplerate.

Video encoders are also partially validated by encoding few resolutions.
These resolutions are not meant to cover cdd profile requirements. These
are taken from CodecEncoderTest class. This is done to reduce regression
duration of CodecEncoderTest.

Bug: 186688670
Test: atest android.mediav2.cts.EncoderValidationTest
Test: atest android.mediav2.cts.CodecEncoderTest

Change-Id: I57a52062a69df13662e09991d4196c8ab20de62b
9 files changed