Add support for solo runners. (#3238)
Add support for solo runners. (#3238)

Allows us to parallelize the bazel builds, bringing our CI response time down from 45-60 minutes to roughly 10 minutes.
randallli/material-components-ios,randallli/material-components-ios,randallli/material-components-ios,material-components/material-components-ios,material-components/material-components-ios,material-components/material-components-ios,randallli/material-components-ios,randallli/material-components-ios,material-components/material-components-ios,material-components/material-components-ios,randallli/material-components-ios