Add sample_updater style check to PREUPLOAD.cfg

Test: N/A
Change-Id: I13f4295a85d50c0a63cac5680e7a3200b0e6c909
diff --git a/PREUPLOAD.cfg b/PREUPLOAD.cfg
index b5f5f03..878651c 100644
--- a/PREUPLOAD.cfg
+++ b/PREUPLOAD.cfg
@@ -4,3 +4,8 @@
 [Builtin Hooks Options]
 # Handle native codes only.
 clang_format = --commit ${PREUPLOAD_COMMIT} --style file --extensions c,h,cc,cpp
+
+[Hook Scripts]
+checkstyle_hook = ${REPO_ROOT}/prebuilts/checkstyle/checkstyle.py --sha ${PREUPLOAD_COMMIT}
+                  -fw sample_updater/
+