switch SDK/NDK/gradle buildserver provisioning to shell scripts

This converts the SDK, NDK, and gradle chef recipes to vagrant provisioning shell scripts. Those recipes were just shell scripts anyway, forced into that ugly ruby/chef syntax. Hopefully this will make things easier to maintain since simple bash is easier for most devs than ruby/chef. Also, it might speed up the provisioning a little bit since the whole script is sent to the VM then executed, rather than sent line-by-line. Additionally, the SDK components are now installed using android update sdk so we do not need to duplicate Google's crazy kludges with that stuff.