Add GitHub Actions to validate gradle wrapper files

It's very important to ensure gradle-wrapper.jar files
in this repository are validated by the official tools.

Signed-off-by: utzcoz <utzcoz@outlook.com>

.github/workflows/gradle-wrapper-validation.yml

@@ -0,0 +1,14 @@
+name: "Validate Gradle Wrapper"
+
+on: [push, pull_request]
+
+permissions:
+  contents: read
+
+jobs:
+  validation:
+    name: Validation
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: gradle/wrapper-validation-action@v2