Allow snapshotctl to create ota_metadata_file.

When snapshotctl merge is called on sys.boot_completed
and /metadata/ota/state does not exist, it now tries
to initialize it by creating one.

Test: no selinux denials on boot
Bug: 143551390
Change-Id: I6ee268270e8f788d90610d7a1a90f252ea9baa3a
1 file changed