Update patch version for release

New version is v1.2.9-dev

R=ager

Change-Id: I2863a6349995acdd49f78ee598f5d290fc233b26
diff --git a/src/main/java/com/android/tools/r8/Version.java b/src/main/java/com/android/tools/r8/Version.java
index 3639d9e..210a632 100644
--- a/src/main/java/com/android/tools/r8/Version.java
+++ b/src/main/java/com/android/tools/r8/Version.java
@@ -11,7 +11,7 @@
 
   // This field is accessed from release scripts using simple pattern matching.
   // Therefore, changing this field could break our release scripts.
-  public static final String LABEL = "v1.2.8-dev";
+  public static final String LABEL = "v1.2.9-dev";
 
   private Version() {
   }