Stub the oemlock operations when the PersistentDataBlock is not supported

The PersistentDataBlockService is not a compulsory component of framework thus we need to
handle cases when the PersistentDataBlockService is unavailable.

Bug: 132943408
Bug: 123777418
Test: toggle the oemlock in setting menu.

Change-Id: I59eec0a4905b588bf261b8447ad4b4e26ba5278d
1 file changed