Resolve "Add minimal empty application"

Closes #1 (closed)

android/app/src/debug/AndroidManifest.xml

+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="org.benoitharrault.sudoku">
+    <!-- Flutter needs it to communicate with the running application
+         to allow setting breakpoints, to provide hot reload, etc.
+    -->
+    <uses-permission android:name="android.permission.INTERNET"/>
+</manifest>