Remove FingerprintStateViewModel.

Since FingerprintStateViewModel is too general as a view model, this CL
removes it and adds more concrete flows in FingerprintSettingsViewModel
and FingerprintEnrollViewModel.

Test: atest FingerprintManagerInteractorTest
Test: atest FingerprintSettingsViewModelTest
Test: Verified enroll/deletion/renaming/authentication flows on Settings

Change-Id: I3a0662195c4989de0813b92bccda9d36a7f7e32a