Merge "DO NOT MERGE: Bump CTS and CTS Verifier to 6.0_r15" into marshmallow-cts-dev am: 1d8c12aa80  -s ours am: 7f203e5d1f  -s ours am: 4c4a28cb3f  -s ours
am: a0a1ce2a09

Change-Id: Icdcc69c8a3fe7725c4d6f8a77b135fd1a37b3cdd