Update comment about robotests' dummy ColorDisplayController.

Bug: None
Test: None
Change-Id: Iadc38a3430b9002ee106782eeced350921581a29
diff --git a/tests/robotests/src/com/android/internal/app/ColorDisplayController.java b/tests/robotests/src/com/android/internal/app/ColorDisplayController.java
index 74e7d8a..e31ba51 100644
--- a/tests/robotests/src/com/android/internal/app/ColorDisplayController.java
+++ b/tests/robotests/src/com/android/internal/app/ColorDisplayController.java
@@ -16,8 +16,8 @@
 package com.android.internal.app;
 
 /**
- * Fake controller to make robolectric test compile. Should be removed when Robolectric supports
- * API 25.
+ * Fake controller to make robolectric test compile. This is necessary since
+ * ColorDisplayController is not part of Android's API.
  */
 public class ColorDisplayController {