Fix race condition is commitCheckpoint

If cp_commitCheckpoint is called twice at the same time, the second call
to setBowState will fail.

Add lock to remove possibility, and protect all uses of isCheckpointing

Bug: 138952436
Test: Boots after flashing in checkpoint mode
Change-Id: I131298adc506c3c176774d15e642b13d5f991087
1 file changed