Add PREUPLOAD.cfg file to enable repo checkstyle hooks

fixes: 65162750
Change-Id: I42dd2699d1966cf509f475a34e623ce449e87213
diff --git a/PREUPLOAD.cfg b/PREUPLOAD.cfg
new file mode 100644
index 0000000..f3db20e
--- /dev/null
+++ b/PREUPLOAD.cfg
@@ -0,0 +1,2 @@
+[Hook Scripts]
+checkstyle_hook = ${REPO_ROOT}/prebuilts/checkstyle/checkstyle.py --sha ${PREUPLOAD_COMMIT}