Prepare TEST_MAPPING for presubmit tests

Putting the tests for postsubmit first. Switch to presubmit once we
verify they are not flaky.

Bug: 142866491
Test: atest --test-mapping frameworks/av/media/libstagefright
Test: atest --test-mapping frameworks/av/media/codec2
Change-Id: I1cbb81434b49288de85b57c7749670be585edc58
2 files changed