Update CTS version to 2.1_r2.

Change-Id: I9ce70318eb0d8443f6d23379a41f2478768abdee
diff --git a/tools/host/src/com/android/cts/Version.java b/tools/host/src/com/android/cts/Version.java
index b3f6766..6477b1d 100644
--- a/tools/host/src/com/android/cts/Version.java
+++ b/tools/host/src/com/android/cts/Version.java
@@ -18,7 +18,7 @@
 
 public class Version {
     // The CTS version string
-    private static final String version = "2.1_r1";
+    private static final String version = "2.1_r2";
     
     private Version() {
         // no instances allowed