[BiometricsV2] Refine fingerprint ui and flow

1. Fix "No thanks" become 2 lines, and fix the status when new
   fingerprint enrolled.
2. Fix Finish page shows again after pressing back from a new Finish
   page
3. Fix FindSensor page shows again after max number of fingerprint
   has reached.
4. Add missing tests, and remove some bypass-only tests

Bug: 279134177
Bug: 279380583
Bug: 279386539
Bug: 279394069
Test: atest FingerprintEnrollIntroViewModelTest
    FingerprintEnrollFindSensorViewModelTest
    FingerprintEnrollEnrollingViewModelTest
    FingerprintEnrollmentViewModelTest FingerprintEnrollmentActivityTest
Test: manually test 1, 2, and 3
Change-Id: I3797ceed8e7d6c10a4b4711f8bff8d7f222f0923

src/com/android/settings/biometrics2/ui/viewmodel/FingerprintEnrollIntroViewModel.java

@@ -107,8 +107,6 @@ public class FingerprintEnrollIntroViewModel extends AndroidViewModel {
                             enrollableValue != null ? enrollableValue : ENROLLABLE_STATUS_DEFAULT);
                     mPageStatusLiveData.setValue(status);
                 });
-
-        updateEnrollableStatus();
     }
 
     /**
@@ -133,6 +131,7 @@ public class FingerprintEnrollIntroViewModel extends AndroidViewModel {
      * Get enrollable status and hasScrollToBottom live data
      */
     public LiveData<FingerprintEnrollIntroStatus> getPageStatusLiveData() {
+        updateEnrollableStatus();
         return mPageStatusLiveData;
     }