Merge pull request #437 from nightfallsad/feature/flutter_1.9_androidx_upgrade

androidx adaptation

README.md

@@ -14,7 +14,7 @@ A next-generation Flutter-Native hybrid solution. FlutterBoost is a Flutter plug
 <a name="bf647454"></a>
 
 # Prerequisites
-You need to add Flutter to your project before moving on.The version of the flutter SDK requires v1.9.1+hotfix.5, or it will compile error.
+You need to add Flutter to your project before moving on.The version of the flutter SDK requires v1.9.1+hotfixes, or it will compile error.
 
 # Getting Started
 

README_CN.md

@@ -13,7 +13,7 @@
 
 
 # 前置条件
-在继续之前，您需要将Flutter集成到你现有的项目中。flutter sdk 的版本需要 v1.5.4-hotfixes，否则会编译失败.
+在继续之前，您需要将Flutter集成到你现有的项目中。flutter sdk 的版本需要 v1.9.1-hotfixes，否则会编译失败.
 
 # 安装
 

android/src/main/java/com/idlefish/flutterboost/BoostPluginRegistry.java

@@ -2,7 +2,7 @@ package com.idlefish.flutterboost;
 
 import android.app.Activity;
 import android.content.Context;
-import android.support.annotation.Nullable;
+import androidx.annotation.Nullable;
 import com.idlefish.flutterboost.interfaces.IContainerRecord;
 import io.flutter.app.FlutterPluginRegistry;
 import io.flutter.embedding.engine.FlutterEngine;