CtsVideoTestCases: Refactor Performance tests

Create base classes that can be reused in concurrent tests
that are being developed.

Also fix a typo in bitrate used for 480p (use 2mbps instead
of 200kbps)

Change the buffer size from fileLength*2 to fileLength

Bug: 179084588
Test: atest android.video.cts.CodecEncoderPerformanceTest
Test: atest android.video.cts.CodecDecoderPerformanceTest

Change-Id: I64bec4683f07accbbe589914f95776ba53f189c2
Merged-In: I64bec4683f07accbbe589914f95776ba53f189c2
(cherry picked from commit a794b7d78fa4e8398cf04db7e02a46cc97e8526d)
5 files changed