Point to the new checkstyle location for PREUPLOAD hook.

This change depends on r.android.com/314437

Bug: 33666900
Test: None
Change-Id: I6ba827da3e09f0bf8e180bcc4ccb72f178856d32
diff --git a/PREUPLOAD.cfg b/PREUPLOAD.cfg
index d2f7a92..2673295 100644
--- a/PREUPLOAD.cfg
+++ b/PREUPLOAD.cfg
@@ -1,5 +1,5 @@
 [Hook Scripts]
-checkstyle_hook = ../../../../development/tools/checkstyle/checkstyle.py --sha ${PREUPLOAD_COMMIT}
+checkstyle_hook = ${REPO_ROOT}/prebuilts/checkstyle/checkstyle.py --sha ${PREUPLOAD_COMMIT}
 
 [Builtin Hooks]
 commit_msg_bug_field = true