Updates post UICircle merge

* renamed ChangeColor to UICircleChangeColor for clarity
* renamed ChangeDensity to UICircleChangeDensity for clarity
* removed unnecessary usings
* updates scene to match UI control start positions

Examples/UICircleProgress/UICircleChangeColor.cs

@@ -1,9 +1,7 @@
-using System.Collections;
-using System.Collections.Generic;
-using UnityEngine;
+using UnityEngine;
 using UnityEngine.UI.Extensions;
 
-public class ChangeColor : MonoBehaviour
+public class UICircleChangeColor : MonoBehaviour
 {
     public GameObject TargetUICircle;
     private Color baseColor;

Examples/UICircleProgress/UICircleChangeDensity.cs

@@ -1,10 +1,8 @@
-using System.Collections;
-using System.Collections.Generic;
-using UnityEngine;
+using UnityEngine;
 using UnityEngine.UI;
 using UnityEngine.UI.Extensions;
 
-public class ChangeDensity : MonoBehaviour
+public class UICircleChangeDensity : MonoBehaviour
 {
     public GameObject MultiColorObject;
     public GameObject TextOutputObject;