Fix Docker build to match Google Cloud Build script

[politician]

Since the upgrade to OpenJDK 11 and the latest bazel, the Dockerfile is broken.
This pull request fixes it and ensures greater futureproofness by using the same script as GCB

[politician]

@mikelalcon @hsudhof I have signed the CLA, you can re-scan it

[politician]

@hsudhof Any chance you can merge this PR?

I build a Docker image for https://github.com/olivr/copybara-action and I'd rather use the Dockerfile from this repo than maintain my own Dockerfile.
Besides I am sure others will benefit from a working Dockerfile.

Thank you

[gjasny]

Is there a reason why you removed buildozer and buildifier from the image?

[politician]

I believe there was no reason for them to be in here in the first place?
They could be re-added but I think the less extraneous dependencies the better.

[gjasny]

Some copybara rules depend on those two binaries. When I run copybara from the docker image I'd have to provide them via some file or container mapping. This could get more complicated than necessary.

If there are no technical reasons to exclude them I'd prefer keeping them in the image.

[politician]

@gjasny Indeed they are even at the beginning of the docs 🙊
I've just added them back. Please let me know if you see anything else.

[mikelalcon]

Hi! sorry for the delay. I think the change looks good in general, just one question about jdk.

[qqaatw]

Hi, is there any update?

Thanks for the fix, BTW.

[mikelalcon]

Merged