Add volume controll interface in settinglib

Bug: 148756190
Test: make -j42 RunSettingsLibRoboTests
Change-Id: I3bfdb5bf48d27ce17ceffc3db28bec7e12357ab1

packages/SettingsLib/src/com/android/settingslib/media/InfoMediaDevice.java

@@ -73,6 +73,21 @@ public class InfoMediaDevice extends MediaDevice {
         return true;
     }
 
+    @Override
+    public void requestSetVolume(int volume) {
+        mRouterManager.requestSetVolume(mRouteInfo, volume);
+    }
+
+    @Override
+    public int getMaxVolume() {
+        return mRouteInfo.getVolumeMax();
+    }
+
+    @Override
+    public int getCurrentVolume() {
+        return mRouteInfo.getVolume();
+    }
+
     @Override
     public void disconnect() {
         //TODO(b/144535188): disconnected last select device

packages/SettingsLib/src/com/android/settingslib/media/MediaDevice.java

@@ -108,6 +108,59 @@ public abstract class MediaDevice implements Comparable<MediaDevice> {
      */
     public abstract boolean isConnected();
 
+    /**
+     * Request to set volume.
+     *
+     * @param volume is the new value.
+     */
+    public void requestSetVolume(int volume) {
+    }
+
+    /**
+     * Get max volume from MediaDevice.
+     *
+     * @return max volume.
+     */
+    public int getMaxVolume() {
+        return 100;
+    }
+
+    /**
+     * Get current volume from MediaDevice.
+     *
+     * @return current volume.
+     */
+    public int getCurrentVolume() {
+        return 0;
+    }
+
+    /**
+     * Get application package name.
+     *
+     * @return package name.
+     */
+    public String getClientPackageName() {
+        return null;
+    }
+
+    /**
+     * Get application label from MediaDevice.
+     *
+     * @return application label.
+     */
+    public String getClientAppLabel() {
+        return null;
+    }
+
+    /**
+     * Get application label from MediaDevice.
+     *
+     * @return application label.
+     */
+    public int getDeviceType() {
+        return mType;
+    }
+
     /**
      * Rules:
      * 1. If there is one of the connected devices identified as a carkit, this carkit will