Update downstream Getting started & Installation guides to reflect corrected YAML examples (DBZ-6153)

DBZ-6153 corrected some errors in the YAML examples for deploying connectors downstream. The updated doc uses a shared file that relies heavily on conditionalization and attribute variables to render the information that is relevant in the context of each connector. 

The downstream OCP installation guide relies on the same shared file. For the RHEL installation guide, and the Getting Started guide, the content is hard-coded in the downstream files.  The deployment example in each of these guides is based on the use of the MySQL connector. The updated upstream content cannot be used as-is in these contexts. 

This issue covers the work required to ensure that the correct version of the YAML file renders in each of these contexts.

This change requires downstream updates only, including re-homing include directives, some direct content edits, and defining attribute values to apply to included content in the OCP installation guide.