Add non system overlay flag to RequestManageCredentials

Bug: 205150380
Test: Manual testing with Settings and TestDPC
Change-Id: I7c23442e143a6d74935945e6f5e4ce5ce0ef77f0
Merged-In: I7c23442e143a6d74935945e6f5e4ce5ce0ef77f0
diff --git a/src/com/android/settings/security/RequestManageCredentials.java b/src/com/android/settings/security/RequestManageCredentials.java
index 1a8da67..6a1d40a 100644
--- a/src/com/android/settings/security/RequestManageCredentials.java
+++ b/src/com/android/settings/security/RequestManageCredentials.java
@@ -16,6 +16,8 @@
 
 package com.android.settings.security;
 
+import static android.view.WindowManager.LayoutParams.SYSTEM_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS;
+
 import android.annotation.Nullable;
 import android.app.Activity;
 import android.app.admin.DevicePolicyEventLogger;
@@ -120,6 +122,7 @@
                 .setStrings(mCredentialManagerPackage)
                 .write();
         setContentView(R.layout.request_manage_credentials);
+        getWindow().addSystemFlags(SYSTEM_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS);
         mIsLandscapeMode = getResources().getConfiguration().orientation
                 == Configuration.ORIENTATION_LANDSCAPE;
 
@@ -211,7 +214,9 @@
     private void loadButtons() {
         mButtonPanel = findViewById(R.id.button_panel);
         Button dontAllowButton = findViewById(R.id.dont_allow_button);
+        dontAllowButton.setFilterTouchesWhenObscured(true);
         Button allowButton = findViewById(R.id.allow_button);
+        allowButton.setFilterTouchesWhenObscured(true);
 
         dontAllowButton.setOnClickListener(b -> {
             DevicePolicyEventLogger