Get versionCode and versionName with unity.

UnityGetNativeAndroidVersion

  //int vesioncode =  context().getPackageManager().getPackageInfo(context().getPackageName(), 0).versionCode;
  public static int GetVersionCode() {
      AndroidJavaClass contextCls = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
      AndroidJavaObject context = contextCls.GetStatic<AndroidJavaObject>("currentActivity"); 
      AndroidJavaObject packageMngr = context.Call<AndroidJavaObject>("getPackageManager");
      string packageName = context.Call<string>("getPackageName");
      AndroidJavaObject packageInfo = packageMngr.Call<AndroidJavaObject>("getPackageInfo", packageName, 0);
      return packageInfo.Get<int>("versionCode");
  }
  
  //int versionName =  context().getPackageManager().getPackageInfo(context().getPackageName(), 0).versionName;
  public static string GetVersionName() {
      AndroidJavaClass contextCls = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
      AndroidJavaObject context = contextCls.GetStatic<AndroidJavaObject>("currentActivity"); 
      AndroidJavaObject packageMngr = context.Call<AndroidJavaObject>("getPackageManager");
      string packageName = context.Call<string>("getPackageName");
      AndroidJavaObject packageInfo = packageMngr.Call<AndroidJavaObject>("getPackageInfo", packageName, 0);
      return packageInfo.Get<string>("versionName");
  }