Increase helm timeout to 300s

[dbarkowsky]

Summary

Helm default is 300s. We previously allotted 120s, but it times out often. Let's see how 300s does instead.

Checklist

By submitting this pull request, I acknowledge that I have attempted to meet the following:

• a self-review of my code
• commented code particularly in hard-to-understand areas
• corresponding changes to the documentation where required
• changes tested to the best of my ability
• no new errors or non-functional code