Fixed issues in device management APIs

product/modules/agents/android/jax-rs/src/main/java/cdm/api/android/Device.java

@@ -17,6 +17,7 @@
 package cdm.api.android;
 
 import cdm.api.android.util.AndroidAPIUtils;
+import com.google.gson.Gson;
 import com.google.gson.JsonObject;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -70,7 +71,8 @@ public class Device {
 		}
 		switch (status) {
 			case 1:
-				return Response.status(200).entity(result).build();
+				String response = new Gson().toJson(result);
+				return Response.status(200).entity(response).build();
 			case -1:
 				return Response.status(500).entity(msg).build();
 		}
@@ -83,7 +85,7 @@ public class Device {
 		int status = 0;
 		String msg = "";
 		DeviceManagementService dmService;
-		org.wso2.carbon.device.mgt.common.Device device = null;
+		org.wso2.carbon.device.mgt.common.Device device = new org.wso2.carbon.device.mgt.common.Device();
 		try {
 			PrivilegedCarbonContext.startTenantFlow();
 			PrivilegedCarbonContext ctx = PrivilegedCarbonContext.getThreadLocalCarbonContext();
@@ -111,7 +113,8 @@ public class Device {
 		}
 		switch (status) {
 			case 1:
-				return Response.status(200).entity(device).build();
+				String response = new Gson().toJson(device);
+				return Response.status(200).entity(response).build();
 			case -1:
 				return Response.status(500).entity(msg).build();
 		}

product/modules/agents/android/jax-rs/src/main/java/cdm/api/android/util/AndroidAPIUtils.java

@@ -31,7 +31,6 @@ public class AndroidAPIUtils {
 	public static Device convertToDeviceObject(String jsonString) {
 		JsonObject obj = new Gson().fromJson(jsonString, JsonObject.class);
 		Device device = new Device();
-
 		device.setType(DeviceManagementConstants.MobileDeviceTypes.MOBILE_DEVICE_TYPE_ANDROID);
 		if (obj.get(AndroidConstants.DeviceConstants.DEVICE_MAC_KEY) != null) {
 			device.setDeviceIdentifier(