Add OEM-configurable flag for OAT artifact deletion

As per feedback from OEM partners, we are adding a configurable build
time flag that determines whether hibernation performs OAT artifact
deletion. This flag is only for this specific sub-optimization the other
parts of hibernation would occur regardless of the flag.

Bug: 183563260
Test: atest AppHibernationServiceTest
Change-Id: Ic798f3ed4c340b84f4c97f118e07767d36211a97