Wait for confirm button, if present.

In the older prompt this button was hidden, but never gone.

Bug: 272510026
Test: atest android.server.biometrics.cts.BiometricsAtomsTests
Change-Id: Iffff0a31b7117e48aa33772b8d03a4f64832915b
diff --git a/hostsidetests/biometrics/app/src/android/server/biometrics/cts/app/BiometricsAtomsHostSideTests.java b/hostsidetests/biometrics/app/src/android/server/biometrics/cts/app/BiometricsAtomsHostSideTests.java
index 450cbb6..b136cb0 100644
--- a/hostsidetests/biometrics/app/src/android/server/biometrics/cts/app/BiometricsAtomsHostSideTests.java
+++ b/hostsidetests/biometrics/app/src/android/server/biometrics/cts/app/BiometricsAtomsHostSideTests.java
@@ -188,7 +188,8 @@
                 Utils.waitForIdleService();
 
                 // The framework may require confirmation even if not requested by the API
-                final UiObject2 confirmButton = findView(VIEW_BIOMETRIC_PROMPT_CONFIRM_ID);
+                final UiObject2 confirmButton = mDevice.wait(Until.findObject(
+                        getBySelector(VIEW_BIOMETRIC_PROMPT_CONFIRM_ID)), WAIT_MS);
                 if (confirmButton != null) {
                     Log.d(TAG, "click confirmButton");
                     confirmButton.click();
@@ -206,10 +207,6 @@
         return By.res(mUiPackage, id);
     }
 
-    private UiObject2 findView(String id) throws Exception {
-        return mDevice.findObject(getBySelector(id));
-    }
-
     private static List<Integer> getAcquiredCodesForEnroll(int sensorId) throws Exception {
         if (isFace(sensorId)) {
             return FACE_ENROLL_ACQUIRED_MESSAGES;