feat(flutter): 接入 flutter_native_splash 原生开屏

android/app/src/main/res/drawable/launch_background.xml

@@ -1,6 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
-<!-- Author: fruit.com.cn -->
-
 <layer-list xmlns:android="http://schemas.android.com/apk/res/android">
     <item android:drawable="@color/splash_background" />
 </layer-list>

android/app/src/main/res/drawable/splash_transparent.xml

@@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!-- Author: fruit.com.cn -->
-
-<shape xmlns:android="http://schemas.android.com/apk/res/android">
-    <solid android:color="@android:color/transparent" />
-</shape>