Add implementation alternatives for OemLockManager.

The OEM lock can be implemented with the persistent data block or the
OemLock HAL.

Test: gts-tradefed run gts -m GtsOemLockServiceTestCases -t com.google.android.oemlock.gts.OemLockServiceTest
Bug: 34766843
Change-Id: I16b31785d9af58212a050a299ef024be3139f0c6