fs_mgr: Fix disable-verity for verifyatboot partitions

This allows a remount to be performed on partitions which have been
verified at boot, without causing the verity service to complain of
"corrupted" blocks that could have been modified as a result of a
remount (while the verity checksum remained unchanged).

(cherry picked from commit dd78ae75ff91f19106a4c3944fe3170602ac2334)

Bug: 32638755
Test: Compile
Change-Id: I77cf7dd20ee5c5f5dac80f73f292e32583fe5906
1 file changed