This reverts the upgrade to Android Studio 3.0 Beta 3 from commit
22ae3aa5b6 due to an upstream decision.
From the release updates: "Due to an issues with the Android Plugin for
Gradle in Beta 3 (64527520), we've pulled it down and recommend that you
not accept the update. If you already did, you can go back to Beta 2 by
downloading here." [0]
[0]: https://androidstudio.googleblog.com/2017/08/android-studio-30-beta-3-is-now.html
Added the `androidStudioPackages` attribute containing both
the `stable` and `preview` channels.
Changed the attribute `andorid-studio` to point to
`androidStudioPackages.stable`
Added the attribute `andorid-studio-preview` pointing to
`androidStudioPackages.preview`
I have tested this package using the new koltin support,
no issues found yet.
