fix null safety

android/app/build.gradle

@@ -24,12 +24,16 @@ if (flutterVersionName == null) {
 apply plugin: 'com.android.application'
 apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
 
+def keystoreProperties = new Properties()
+def keystorePropertiesFile = rootProject.file('key.properties')
+if (keystorePropertiesFile.exists()) {
+    keystoreProperties.load(new FileInputStream(keystorePropertiesFile))
+}
+
 android {
     compileSdkVersion 30
 
     defaultConfig {
-        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
-        applicationId "com.mokkon.fcs.fcs"
         minSdkVersion 21
         targetSdkVersion 30
         versionCode flutterVersionCode.toInteger()

android/app/src/dev/AndroidManifest.xml

@@ -1,5 +1,5 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="com.mokkon.fcs_dev.fcs">
+    package="com.mokkon.fcs.fcs">
     <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
 
     <!-- io.flutter.app.FlutterApplication is an android.app.Application that
@@ -15,7 +15,6 @@
             android:name=".MainActivity"
             android:launchMode="singleTop"
             android:theme="@style/LaunchTheme"
-            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
             android:hardwareAccelerated="true"
             android:windowSoftInputMode="adjustResize">
             <!-- This keeps the window background of the activity showing

android/app/src/main/AndroidManifest.xml

@@ -1,7 +1,6 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.mokkon.fcs.fcs">
    <application
-        android:label="fcs"
         android:icon="@mipmap/ic_launcher">
         <activity
             android:name=".MainActivity"

android/app/src/main/java/com/mokkon/fcs/fcs/Application.java

@@ -0,0 +1,13 @@
+package com.mokkon.fcs.fcs;
+
+ import io.flutter.app.FlutterApplication;
+import io.flutter.plugin.common.PluginRegistry;
+import io.flutter.plugins.GeneratedPluginRegistrant;
+
+
+public class Application extends FlutterApplication  {
+  @Override
+  public void onCreate() {
+    super.onCreate();
+  }
+}

android/app/src/main/res/values/strings.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="app_name">FCS</string>
+</resources>