implement android import, update android project and build for release

android/src/main/AndroidManifest.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-      package="com.omigamedev"
+      package="com.omixlab.panopainter"
       android:versionCode="1"
       android:versionName="1.0">
     <uses-permission android:name="android.permission.INTERNET" />
@@ -9,13 +9,11 @@
     <application android:label="@string/app_name"
                  android:icon="@mipmap/ic_launcher"
                  android:allowBackup="false"
-                 android:hasCode="false"
                  android:theme="@android:style/Theme.NoTitleBar.Fullscreen">
-        <activity android:name="android.app.NativeActivity"
+        <activity android:name=".MainActivity"
                   android:label="@string/app_name"
                   android:configChanges="orientation|keyboardHidden"
                   android:screenOrientation="sensorLandscape"
-                  android:noHistory="true"
                   android:windowSoftInputMode="adjustResize">
             <meta-data android:name="android.app.lib_name"
                        android:value="native-lib" />