ANDROID: Add kconfig to make dm-verity check_at_most_once default enabled

This change adds a kernel config for default enable
the check_at_most_once dm-verity option. This is to give us
the ability to enforce the usage of at_most_once
for entry-level phones.

Change-Id: Id40416672c4c2209a9866997d8c164b5de5dc7dc
Signed-off-by: Patrik Torstensson <totte@google.com>
Bug: 72664474