title: Find versionnumber and versioncode of apk generated by android studio
body: <p>I know that .apk files are zip files and when we extract them can parse manifest file inorder to finding some information about the app. It is very useful for someone like me that is going to create an app-store. Actually at least I can find the version name and version code of the app.</p>
  
  <p>But in the android-studio when we build a signed apk the version name and version code is not defining in the manifest file. We should define them in the <code>build.gradle</code>  file. So now in my app-store when users upload the files how can I find the version code and version name and detect that is not same with old versions?</p>