Update github action gradle-check to use pull_request_target for acce…

…ssing token (#3728) (#3731)

* Check out gradle

Signed-off-by: Peter Zhu <zhujiaxi@amazon.com>

* Tweak titles

Signed-off-by: Peter Zhu <zhujiaxi@amazon.com>
(cherry picked from commit 4f7bf08)

Co-authored-by: Peter Zhu <zhujiaxi@amazon.com>

.github/workflows/gradle-check.yml

@@ -1,5 +1,7 @@
-name: Jenkins Gradle Check
-on: [pull_request]
+name: Gradle Check (Jenkins)
+on:
+  pull_request_target:
+    types: [opened, synchronize, reopened]
 
 jobs:
   gradle-check: