Hide background when identity check auth is requested

Flag: android.hardware.biometrics.flags.mandatory_biometrics
Fixes: 354014097
Test: atest UtilsTest
Change-Id: I3af06fd9dca2bdc306496f1db832e1d1e2bfe8d2

src/com/android/settings/MainClear.java

@@ -188,7 +188,7 @@ public class MainClear extends InstrumentedFragment implements OnGlobalLayoutLis
                     false /* biometricsAuthenticationRequested */,
                     userId)) {
                 Utils.launchBiometricPromptForMandatoryBiometrics(this, BIOMETRICS_REQUEST,
-                        userId);
+                        userId, false /* hideBackground */);
                 return;
             }
         }