Prevent drawing on top of DevicePickerActivity

Bug: 182584940
Change-Id: I8b27b397bce1708a42b96b1b647c64e23142c468
(cherry picked from commit 68f799a4c6afc3b96b354d1b8b970780bb6cf58a)
diff --git a/src/com/android/settings/bluetooth/DevicePickerActivity.java b/src/com/android/settings/bluetooth/DevicePickerActivity.java
index 77e8ba4..a4f025b 100644
--- a/src/com/android/settings/bluetooth/DevicePickerActivity.java
+++ b/src/com/android/settings/bluetooth/DevicePickerActivity.java
@@ -16,6 +16,8 @@
 
 package com.android.settings.bluetooth;
 
+import static android.view.WindowManager.LayoutParams.SYSTEM_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS;
+
 import android.os.Bundle;
 
 import androidx.fragment.app.FragmentActivity;
@@ -31,6 +33,7 @@
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
+        getWindow().addSystemFlags(SYSTEM_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS);
         setContentView(R.layout.bluetooth_device_picker);
     }
 }