Add dnd messages + calls senders image resource

Add a visual representation of the call or message senders that can
bypass DND.

Test: manual
Bug: 151845457
Change-Id: Ie7d3598d5993e4c1cd62294ab9e17da47f2b6f76

res/layout/zen_mode_senders_image.xml

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2020 The Android Open Source Project
+
+     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.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+             android:layout_width="match_parent"
+             android:layout_height="wrap_content">
+
+    <ImageView
+        android:id="@+id/zen_mode_settings_senders_image"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content" />
+</FrameLayout>