Version 3.1.21

Bug: 199043500
Bug: 198776409
Bug: 197066019
Change-Id: I3d85db75ed6697168e2fa0453a193fc2ce2c69b0
diff --git a/src/main/java/com/android/tools/r8/Version.java b/src/main/java/com/android/tools/r8/Version.java
index 3e29f7e..f37f718 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 = "3.1.20";
+  public static final String LABEL = "3.1.21";
 
   private Version() {
   }