[bazel] Rename `remote` config to `rbe`

In the Selenium project, `remote` may refer to a number of different
things:

 * A driver running on the local machine, but not in process
 * A driver running remotely, in Grid or a Selenium As A Service provider
 * The remote protocol we're using
 * The `remote` Bazel config for builds

To reduce this plethora of options, renaming the Bazel `remote`
config to `rbe` will help.