fix(build-tools) Build tools failed on sdk update filter

I tried with  `android::build_tools { '19.1': }`

But I get this error
```
Error: /opt/boxen/homebrew/opt/android-sdk/bin/android update sdk --all --no-ui --filter 19.1 returned 1 instead of one of [0]
```
The it worked with this..
```ruby
android::build_tools { 'build-tools-19.1': }
```
@aafwu00 can you take a look to this PR