Prevent UdfpsView from being selectable during a11y enrollment

Touching the sensor area also selects the UdfpsView, which triggers
unnecessary feedback.

Fixes: 187324285
Test: manual
Change-Id: I9761c313d917f11fd42e0d584d6303d2150ce1a0

packages/SystemUI/src/com/android/systemui/biometrics/UdfpsController.java

@@ -624,6 +624,14 @@ public class UdfpsController implements DozeReceiver, HbmCallback {
                     animation.init();
                     mView.setAnimationViewController(animation);
 
+                    // This view overlaps the sensor area, so prevent it from being selectable
+                    // during a11y.
+                    if (reason == IUdfpsOverlayController.REASON_ENROLL_FIND_SENSOR
+                            || reason == IUdfpsOverlayController.REASON_ENROLL_ENROLLING) {
+                        mView.setImportantForAccessibility(
+                                View.IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS);
+                    }
+
                     mWindowManager.addView(mView, computeLayoutParams(animation));
                     mAccessibilityManager.addTouchExplorationStateChangeListener(
                             mTouchExplorationStateChangeListener);