1.按照官方文檔生成簽名文件搅方，修改build文件和manifest文件：
https://flutterchina.club/android-release/
2.注意AndroidX的適配問(wèn)題，詳見：
https://flutter.dev/docs/development/packages-and-plugins/androidx-compatibility#recommended-use-android-studio-to-migrate-your-app
3.release模式混淆壓縮注意事項(xiàng)：
在 "proguard-rules.pro" 文件中姨涡，我們就要加入 -dontwarn 語(yǔ)句對(duì)第三方庫(kù)進(jìn)行報(bào)錯(cuò)屏蔽吧慢，否則proguard的代碼混淆無(wú)法進(jìn)行
#Flutter Wrapper
-dontwarn io.flutter.**
-keep class io.flutter.app.** { *; }
-keep class io.flutter.plugin.** { *; }
-keep class io.flutter.util.** { *; }
-keep class io.flutter.view.** { *; }
-keep class io.flutter.** { *; }
-keep class io.flutter.plugins.** { *; }
