This reverts commit 93573de216.
Fails in the devicelab:
```
run:stderr: A problem occurred evaluating project ':app'.
run:stderr: > Could not resolve all files for configuration 'classpath'.2018-10-23T10:46:46.335864:
run:stderr: > Could not find aapt2-proto.jar (com.android.tools.build:aapt2-proto:0.3.1).2018-10-23T10:46:46.335960:
run:stderr: Searched in the following locations:2018-10-23T10:46:46.336048:
```
Automated Flutter integration test suites. Each suite consists of a complete
Flutter app and a flutter_driver specification that drives tests from the UI.
Intended for use with devicelab.