Reset SYSTEM_FIXED flags for hard restricted perms

So that incorrectly SYSTEM_FIXED / denied permissions will be able to
get regrated via the default permission grant policy

This can be removed after all devices have been fixed

Test: Got system into the state with SYSTEM_FIXED / denied permission
      and then silulated an OTA with this change
Bug: 134069814

Change-Id: I7bc986f0d3e69dd60a017f16867182163fd6eecb
(cherry picked from commit 0891123822d6173686e9772c3265b72c27b2b901)