fix: We need TILLER_NAMESPACE set and specifying the namespace flag on install

What does this MR do?

Fixes the Helm v2 guard utility.

We thought we could get rid of the TILLER_NAMESPACE env var, but that is what actually defines where releases are installed in Helm v2.

We had a false positive in our test, so it was hard to detect it.

Screenshots

Manual QA

• Test this change using a Cluster management project