Open APK files - Update FileOpener.java

[SteamWind]

A added the intent of open an apk application. You can fork if you want but now I must try the code first. I think we must to add the permission to install package: But I don't know how to do it automatically.

[don]

Thanks for this pull request. I'm going to leave this open in case other people need the ability to open APK files. I'm not going to merge. In the app where I use this I can't add android.permission.INSTALL_PACKAGES and don't want users opening APKs at this time.