Logging improvements on DevicePolicyManagerService classes:

- Overloaded most Slog methods to support string formatting.
- Uses Locale.ENGLISH on such string formatting calls.
- Fixed logging statements that were using DEBUG inside a method
  (as it wouldn't prevent the calling code to be compiled out when
  it's value is 'false').
- Changed  some secondary classes (i.e., not on DPMS itself) to
  use Slog instead of Log.
- Added some extra info like file name and user id.
- Removed unused variables.

Test: m services
Test: atest FactoryResetterTest FrameworksServicesTests:DevicePolicyManagerTest

Bug: 156263735

Change-Id: Ie15e0c3bd75c845de79f6e724b65578272e45410