Avoid an extra copy for RGBA layers

... as the "conversion" would just be a DoCopy().

Bug: b/213913429
Test: cvd start --gpu_mode=guest_swiftshader
Test: android.hardware.camera2.cts.RecordingTest#testVideoSnapshot[1]
Change-Id: I89fb947d05d246ee93a407528df153a2ae2cdfcd
1 file changed