[Sound panel] Update Ui layout to match with mertial next

please check bug for before/after screenshot.

Bug: 191317779
Test: verified on device
Change-Id: Ia570dde71ce9f18376eaba48102cecde6adb85bb

res/drawable/volume_dialog_button_background_solid.xml

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright (C) 2021 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.
+  -->
+
+<shape xmlns:android="http://schemas.android.com/apk/res/android"
+       xmlns:androidprv="http://schemas.android.com/apk/prv/res/android"
+       android:shape="rectangle">
+    <stroke
+        android:color="@android:color/transparent"
+        android:width="1dp"/>
+    <corners android:radius="20dp"/>
+    <padding
+        android:left="16dp"
+        android:right="16dp"
+        android:top="8dp"
+        android:bottom="8dp" />
+    <solid android:color="?androidprv:attr/colorAccentPrimary" />
+</shape>