Description of problem:

A user tried to follow the release-1.7 README to install the backstage chart, but when running it, they got the latest version of the chart (4.5.8), when they were expecting the version corresponding to the release-1.7 branch (4.4.5).

Prerequisites (if any, like setup, operators/versions):

Steps to Reproduce

Just follow the release-1.7 README to install the backstage chart

Expected results:

I think we should specify the chart version in this `helm install` command. We don't need to maintain it manually, since it can be added to the README template file, and it will be auto-updated by the pre-commit hooks.

Reproducibility (Always/Intermittent/Only Once):

Always