Protect GrantCredentialsPermissionActivity against overlay. am: deddb784d0

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/13021294

Change-Id: I37e60418b8f67f3223692d370ced45aae46a706f

core/java/android/accounts/GrantCredentialsPermissionActivity.java

@@ -55,6 +55,9 @@ public class GrantCredentialsPermissionActivity extends Activity implements View
 
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
+        getWindow().addPrivateFlags(
+                android.view.WindowManager.LayoutParams
+                        .PRIVATE_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS);
         setContentView(R.layout.grant_credentials_permission);
         setTitle(R.string.grant_permissions_header_text);