Enable google_java_format in PREUPLOAD.cfg

By popular demand, enable Java linter preupload hook.

Test: repo upload -n
Change-Id: I63b3fe4b09e0ee5329b29fed6840aff2929a32c1
diff --git a/PREUPLOAD.cfg b/PREUPLOAD.cfg
index a6b1f95..00f34b9 100644
--- a/PREUPLOAD.cfg
+++ b/PREUPLOAD.cfg
@@ -4,6 +4,7 @@
 bpfmt = true
 clang_format = true
 jsonlint = true
+google_java_format = true
 pylint3 = true
 rustfmt = true
 xmllint = true