优化android构建脚本，使runner可正常执行

.github/workflows/build-linux-arm-appimage.yml

@@ -83,6 +83,7 @@ jobs:
           distribution: 'temurin'
 
       - name: Export Java environment variables
+        shell: bash
         run: |
           echo "JAVA_HOME=${JAVA_HOME}" >> $GITHUB_ENV
           echo "ANDROID_SDK_ROOT=${ANDROID_SDK_ROOT:-$ANDROID_HOME}" >> $GITHUB_ENV