Revert "hammerhead: update prebuilt kernel [DO NOT MERGE]" am: 2ad63c3f92 -s ours am: 169fac909e am: c48afbb468 am: 96a31c7a89 * commit '96a31c7a89d5a611a8478fbecd98656d9fa964dc': Revert "hammerhead: update prebuilt kernel [DO NOT MERGE]"