OMX VTS: Use GraphicBuffer utils from libui

Use GraphicBufferMapper and GraphicBufferAllocator for
gralloc buffers. This makes the tests independent of
gralloc version

Bug: 160355727
Test: atest VtsHalMediaOmxV1_0TargetMasterTest \
        VtsHalMediaOmxV1_0TargetComponentTest \
        VtsHalMediaOmxV1_0TargetAudioEncTest \
        VtsHalMediaOmxV1_0TargetAudioDecTest \
        VtsHalMediaOmxV1_0TargetVideoDecTest \
        VtsHalMediaOmxV1_0TargetVideoEncTest

Change-Id: If407ac3d8c0fadc55a8e57627121244a8d5155f8
Merged-In: If407ac3d8c0fadc55a8e57627121244a8d5155f8