Factory Reset flag & minor refinement over flag reset scopes

1. At the step of wiping all namespaces, only wipe namespaces with
recorded access by a package. If a namespace is not even accessed by any
package, then resetting it most likely won't make any changes.
Restricting the scope can slightly make the reset less aggressive.
2. In performScopedReset step, if the package hasn't been recorded to
access any namespace, reset nothing rather than reset all namespaces.
"reset all" will happen on the next level any way.
3. Allowlist namespace "configuration" from RescueParty resets, so that
we can use it to contain flags for RescueParty itself.
4. Add a flag which can disable factory reset(but by default still
enabling it) into namespace "configuration".

Test: atest RescuePartyTest
Bug: 162425385
Change-Id: Ie2fbd531535fcaed31c72331b01453e48777eacf