Add startup-script to install Ops Agent

[mittz]

Add the startup-script script resources/scripts/startup-script/examples/install_cloud_ops_agent.sh to support users to install Ops Agent in VM which doesn't have any monitoring/logging agents if they would like. For more details on the test cases I covered, please refer to the ticket for this update.

Submission Checklist

• Have you installed and run this change against pre-commit? pre-commit install
• Are all tests passing? make tests
• If applicable, have you written additional unit tests to cover this
  change?
• Is unit test coverage still above 80%?
• Have you updated any application documentation such as READMEs and user
  guides?
• Have you followed the guidelines in our Contributing document?

[heyealex]

This looks really good and it's really cleanly implemented. My only comments on generalizing this a bit further.

[mittz]

Thank you for your review and comments. I expanded the condition similar to install_ansible.sh.