Parallelize Bytebuffer copy in checksum

Checksum methods cost too much time, especially when the video is
high resolution. Two cases in VideoDecoderValidationTest can take
10 mins and time out. Parallelizing the step of copy ByteBuffer to
Byte Array reduces run time by ~60%.

Bug: 269700364
Test: atest VideoDecoderValidationTest CodecDecoderTest CodecDecoderValidationTest

Change-Id: I7af492e3253ec307b0b74e745dbd70907a8a2ba8
1 file changed