Prevent overlay drawing on top of Bluetooth pairing dialog

Bug: 155648639
Change-Id: I99643ee9084f3a9bc1ad9a459ac27c587d832c91
Merged-In: I99643ee9084f3a9bc1ad9a459ac27c587d832c91

src/com/android/settings/bluetooth/BluetoothPairingDialog.java

@@ -26,6 +26,8 @@ import android.content.IntentFilter;
 import android.os.Bundle;
 import android.support.annotation.VisibleForTesting;
 
+import static android.view.WindowManager.LayoutParams.PRIVATE_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS;
+
 /**
  * BluetoothPairingDialog asks the user to enter a PIN / Passkey / simple confirmation
  * for pairing with a remote Bluetooth device. It is an activity that appears as a dialog.
@@ -63,6 +65,8 @@ public class BluetoothPairingDialog extends Activity {
     @Override
     protected void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
+
+        getWindow().addPrivateFlags(PRIVATE_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS);
         Intent intent = getIntent();
         mBluetoothPairingController = new BluetoothPairingController(intent, this);
         // build the dialog fragment