Update version for release 1.4.22-dev.

R=ricow@google.com

Change-Id: Ia079b32e055c27658be70fb100b512f37523591c
diff --git a/src/main/java/com/android/tools/r8/Version.java b/src/main/java/com/android/tools/r8/Version.java
index b500296..7686444 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 = "1.4.21-dev";
+  public static final String LABEL = "1.4.22-dev";
 
   private Version() {
   }