Fix accidental implicit fallthroughs -Wimplicit-fallthrough was printing warnings for these, they look like real errors. Fix them and re-enable the error. Bug: 144040966 Test: treehugger Merged-In: I818e18a995760f17b85b4c72ee577e531fa2a601 Change-Id: I818e18a995760f17b85b4c72ee577e531fa2a601 (cherry picked from commit bfcf9140fe61eb3d3830daa396ed1992fe613303)