build(action): 添加用于验证 Gradle Wrapper 的 Action.

增加 Gradle Wrapper 验证过程有利于防范恶意 Pull Request 或恶意 Push, 增强构建安全性.

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

@@ -0,0 +1,10 @@
+name: "Validate Gradle Wrapper"
+on: [push, pull_request]
+
+jobs:
+  validation:
+    name: "Validation"
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: gradle/wrapper-validation-action@v1