Use floating tags in golang imagestream

As discussed previously by email, customer support case 03211616 requests a means to use the latest patch version of a given X.Y golang via imagestreams, with the blocking issue being the lack of X.Y tags for the go-toolset containers on RHCC.

The latter has now been fixed with the latest version also getting a :1.17 tag, and the imagestream source has been modified accordingly, which will get picked up in 4.12. We can now fix this in 4.11.z by backporting this to the imagestream files bundled in cluster-samples-operator.

/cc iwatson@redhat.com fmehta@redhat.com