We have seen one case when bspatch failed likely due to patch
corruption. Since the package has passed verification before, we want
to reboot and retry the patch command again since there's no
alternative for users.
We won't delete the stash before reboot, and the src has passed SHA1
check. If there's an error on the patch, it will fail the package
verification during retry.
Bug: 37855643
Test: angler reboots and retries the update when bspatch fails.
Change-Id: I2ebac9621bd1f0649bb301b9a28a0dd079ed4e1d