UserRestrictionsUtil.isValidRestriction wtfs

UserRestrictionsUtil.isValidRestriction() now does a wtf if a given
restriction is invalid and the caller is the system. Non-system callers
continue to just do Log.e.

Fixes: 129407452
Test: manual
Change-Id: I992a517ab0bd6c479f127728ac0ae79d706d1749
1 file changed