Fix overlapping problem for device admin page

The content of Activate device admin app is overlapping with the title
while scrolling up. That is because the collapsing toolbar needs to
work with the view that supports nested scrolling feature, and this page
hasn't updated the layout to use NestedScrollView. So that caused the
overlapping problem.

Fix: 188184864
Test: visual verified
1) Navigate to Settings > Security > Device admin apps > pick up one to
activate
2) Scrolling the content and see if the content is overlapping with the
title

Change-Id: Ide5ff9ed40202c3b217934db93c82a4861983416

res/layout/device_admin_add.xml

@@ -4,9 +4,9 @@
      Licensed under the Apache License, Version 2.0 (the "License");
      you may not use this file except in compliance with the License.
      You may obtain a copy of the License at
-  
+
           http://www.apache.org/licenses/LICENSE-2.0
-  
+
      Unless required by applicable law or agreed to in writing, software
      distributed under the License is distributed on an "AS IS" BASIS,
      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -21,7 +21,7 @@
     android:layout_height="match_parent"
     android:orientation="vertical">
 
-    <ScrollView
+    <androidx.core.widget.NestedScrollView
         android:layout_width="match_parent"
         android:layout_height="0dip"
         android:layout_weight="1.0"
@@ -173,5 +173,5 @@
             </LinearLayout>
 
         </LinearLayout>
-    </ScrollView>
+    </androidx.core.widget.NestedScrollView>
 </LinearLayout>