Add DO API to get wifi mac address

Bug 25496044

Change-Id: Ib1f0ce4ca10951edcfaa0aa79ae5c2d142a74599

core/java/android/app/admin/DevicePolicyManager.java

@@ -4649,4 +4649,21 @@ public class DevicePolicyManager {
             return false;
         }
     }
+
+    /**
+     * Called by device owner to get the MAC address of the Wi-Fi device.
+     *
+     * @return the MAC address of the Wi-Fi device, or null when the information is not
+     * available. (For example, Wi-Fi hasn't been enabled, or the device doesn't support Wi-Fi.)
+     *
+     * <p>The address will be in the {@code XX:XX:XX:XX:XX:XX} format.
+     */
+    public String getWifiMacAddress() {
+        try {
+            return mService.getWifiMacAddress();
+        } catch (RemoteException re) {
+            Log.w(TAG, "Failed talking with device policy service", re);
+            return null;
+        }
+    }
 }

core/java/android/app/admin/IDevicePolicyManager.aidl

@@ -236,4 +236,5 @@ interface IDevicePolicyManager {
     List<String> getKeepUninstalledPackages(in ComponentName admin);
     boolean isManagedProfile(in ComponentName admin);
     boolean isSystemOnlyUser(in ComponentName admin);
+    String getWifiMacAddress();
 }