Configure JDK 21 and update gradlew permissions

Added setup for JDK 21 and permission for gradlew.

Author: yogeshpaliyal

.github/workflows/generate-aab-file.yml

@@ -17,9 +17,15 @@ jobs:
       - uses: actions/checkout@v4
         with:
           ref: ${{ inputs.ref }}
-    
-      - name: Setting up project
-        uses: ./.github/actions/setup
+
+      - name: Set up JDK 21
+        uses: actions/setup-java@v4
+        with:
+          java-version: '21'
+          distribution: 'jetbrains'
+
+      - name: Grant execute permission for gradlew
+        run: chmod +x ./gradlew
 
       - name: Build Release AAB
         id: buildRelease