Resolve reserved keyword conflict with variable names in path patterns

[aandreassa]

googleapis/google-cloud-ruby#26358 introduced a path variable module, which conflicts with reserved keywords, failing generation.

Current plan is:

1. Introduce an owlbot rule to affected library and unblock generation (adding sufix _param).
2. Add a fix to the generator itself, where keyword names will be properly escaped.

Note: google-cloud-support-v2/.owlbot.rb already contains a similar patch and should be tested on upcoming change. In that example, the word case gets converted to ccase.

For reference, PiperOrigin-RevId: 650374217

Pointers: #1086

[dazuma]

It looks like google-cloud-support-v2 is a different issue. It's not a path parameter, but a local variable in a test case. We probably need to fix that case in the generator as well.

[aandreassa]

#1101 should address the last issue we had on naming the local variables. Once the pending PR's are in, I can get started on the generator release to close this out.