updated: package to be standard across all example apps

using_stepper/android/app/src/main/AndroidManifest.xml

@@ -1,5 +1,5 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="com.yourcompany.usingstepper">
+    package="github.nisrulz.usingstepper">
 
     <!-- The INTERNET permission is required for development. Specifically,
          flutter needs it to communicate with the running application
@@ -13,7 +13,7 @@
          additional functionality it is fine to subclass or reimplement
          FlutterApplication and put your custom class here. -->
     <application android:name="io.flutter.app.FlutterApplication" android:label="using_stepper" android:icon="@mipmap/ic_launcher">
-        <activity android:name=".MainActivity"
+        <activity android:name="github.nisrulz.usingstepper.MainActivity"
                   android:launchMode="singleTop"
                   android:theme="@android:style/Theme.Black.NoTitleBar"
                   android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection"

using_stepper/android/app/src/main/java/github/nisrulz/usingstepper/MainActivity.java

@@ -1,4 +1,4 @@
-package com.yourcompany.usingstepper;
+package github.nisrulz.usingstepper;
 
 import android.os.Bundle;