Update KIND_LOWER.go.tmpl to respect `PollInterval` configuration

[aaronschweig]

Description of your changes

Hello everybody! Thanks for providing this great template as a starting point to get new providers up and running. This PR includes a small addition to the controller template that is used to generate controllers for new kinds. The sample controller for mytype.go already contains the managed.WithPollIntervall option but the template that generates new controllers does not.

I thought it might be useful if the template also includes that new option as it would be pretty tedious to make sure to think of adding this option to every controller that is newly created based on the template!

I hope this change is fine - if not feel free to just close the issue and I will only adjust the template in the concrete provider for myself.

I have:

• [x] Read and followed Crossplane's contribution process.
• [x] Run make reviewable to ensure this PR is ready for review.
• [ ] Added backport release-x.y labels to auto-backport this PR if necessary.

How has this code been tested

I executed the gomplate template once and it ran without any errors, I am not aware of any automated tests, so I hope it is enough!

[jbw976]

This would need a maintainer's approval also, looking at owners.md I see @negz @hasheddan @muvaf 😅

I'm also curious if there's any further automated testing/validation that can help ensure there's no further additions needed to make this change complete 🤔