Update README.md

Author: socheatsok78

README.md

@@ -76,10 +76,10 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: Set up JDK 1.8
+      - name: Set up JDK 21
         uses: actions/setup-java@v4
         with:
-          java-version: 1.8
+          java-version: 21
           distribution: 'temurin'
 
       - name: Setup Android SDK