automl: remove vision samples no longer on cgc (GoogleCloudPlatform#2844)

- [ x] `pom.xml` parent set to latest `shared-configuration`
- [ in progress] Appropriate changes to README are included in PR
- [ ] API's need to be enabled to test (tell us)
- [ ] Environment Variables need to be set (ask us to set them)
- [see below] Tests pass (`mvn -P lint clean verify`)
- [x ] Please **merge** this PR for me once it is approved.

Need to take a look still at modelApi tests (it looks like the entire file is obviated, but could be refactored to test model creation?) Could use a second set of eyes here.

Author: Strykrol