Allow specifying rollout strategy

[ellie]

I'd like to test some changes on cloud, and we need to make this configurable for that to happen.

I've set the default values to be the kubernetes defaults, so this should be a no-op until other configuration occurs.

Description

Type of change

• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

How has this been tested?

Checklist

• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works

[danielxnj]

LGTM