Update rules_java version to 6.4.0 in defs.bzl

java/defs.bzl

diff --git a/java/defs.bzl b/java/defs.bzl
index c765cfa..2ba4933 100644
--- a/java/defs.bzl
+++ b/java/defs.bzl
@@ -18,7 +18,7 @@
 # Do not touch: This line marks the end of loads; needed for PR importing.
 
 _MIGRATION_TAG = "__JAVA_RULES_MIGRATION_DO_NOT_USE_WILL_BREAK__"
-version = "6.3.0"
+version = "6.4.0"
 
 def _add_tags(attrs):
     if "tags" in attrs and attrs["tags"] != None: