Add checkstyle to developers/samples/android

Test: repo upload .
Fixes: 112845515

Change-Id: I9b7f33351207e59f0fe70d275522e419c1bc4783
(cherry picked from commit bcece8fdced86668bdc218bb6906657e21bc72d7)
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}