Hide overlay windows when requesting media projection permission.

Done by setting PRIVATE_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS

Bug: 34170870
Test: manual
Change-Id: I57cb0f390d9a78e721c5ddce49a377d385002753
diff --git a/packages/SystemUI/src/com/android/systemui/media/MediaProjectionPermissionActivity.java b/packages/SystemUI/src/com/android/systemui/media/MediaProjectionPermissionActivity.java
index b2a80f4..4a67868 100644
--- a/packages/SystemUI/src/com/android/systemui/media/MediaProjectionPermissionActivity.java
+++ b/packages/SystemUI/src/com/android/systemui/media/MediaProjectionPermissionActivity.java
@@ -16,6 +16,8 @@
 
 package com.android.systemui.media;
 
+import static android.view.WindowManager.LayoutParams.PRIVATE_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS;
+
 import android.app.Activity;
 import android.app.AlertDialog;
 import android.content.DialogInterface;
@@ -36,6 +38,7 @@
 import android.text.TextUtils;
 import android.text.style.StyleSpan;
 import android.util.Log;
+import android.view.Window;
 import android.view.WindowManager;
 import android.widget.CheckBox;
 import android.widget.CompoundButton;
@@ -146,7 +149,9 @@
         mDialog.getButton(DialogInterface.BUTTON_POSITIVE).setFilterTouchesWhenObscured(true);
 
         ((CheckBox) mDialog.findViewById(R.id.remember)).setOnCheckedChangeListener(this);
-        mDialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
+        final Window w = mDialog.getWindow();
+        w.setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
+        w.addPrivateFlags(PRIVATE_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS);
 
         mDialog.show();
     }