ci: declare contents:read on gradle-wrapper-validation workflow

Signed-off-by: Arpit Jain <arpitjain099@gmail.com>

Author: arpitjain099

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

@@ -4,6 +4,9 @@ on:
     branches: [main]
   pull_request: {}
 
+permissions:
+  contents: read
+
 jobs:
   validation:
     name: "Validation"