Helm Values form discards variables with value "null"

[ibonder]

Describe the bug

Helm Values with specified "null" value are missing from Values form in Release UI, moreover they are not propagated when you press "Save" button after editing the Values from GUI

To Reproduce

1. Let's say, you have a Helm Values, where you have set some value to "null" to avoid it getting a default.
   In my case Helm Chart was a elasticsearch-7.17.3

$ helm get values elasticsearch
USER-SUPPLIED VALUES:
ingress:
  className: null

2. Deploy it as usual using helm install or any pipeline you have
3. Using Lens, go to Helm -> Releases
4. Click on your Release
5. On the right hand you will see the Values form. If you look into the values in it - there will be no null'ed value shown

Expected behavior

I expected the output of helm get values <my-chart> command to be the same as what is displayed in the Values form in a Release details menu

Environment (please complete the following information):

• Lens Version: 2024.1.300751-latest
• OS: macOS Sonoma 14.3.1
• Installation method: .dmg package

[samwho]

Just got bitten by this as well, and it caused an outage because a default value we were explicitly setting to null got reintroduced into our release.