Need a way to specify alternative Maven repo in syndesis-server-config

Previously, in Fuse <= 7.4, we were able to edit the syndesis-server-config and modify or add the maven section of the config to point to our internal Fuse QE Nexus proxy.

The point of that was to:

• prevent bans from maven central when running tests with upstream builds
• provide a way to access productized artifacts stored in the indy repo when running tests with prod builds

This approach is currently impossible with syndesis master, since the operator now reverts all manual changes to the config maps to the hard-coded values specified here.

This will be especially critical once we start getting productized builds, because the built artifacts won't yet be available in any of the hard-coded repos and we'll have no way to set an alternative.