[ShaderGraph][2022.1] Fix 1356725 - incorrect appearance of warning message in Node Settings

[jessebarker]

Purpose of this PR

This PR fixes https://fogbugz.unity3d.com/f/cases/1356725/

The behavior for the HelpBoxRow changed and this instance did not get updated. This change updates the one use (that I could find) that doesn't handle the label setup correctly. With this change, we match the "without" image in the bug report - i.e., the text is both in the correct color and the text wraps so that the whole message is viewable.

Fixed (labeled "without" in the bug report):

Broken (labeled "with" in the bug report):

---

Testing status

Manual testing according to the repro steps in the bug report. I could not find any other uses of HelpBoxRow with message type warning elsewhere in the code base, so, contrary to the claim in the bug, I could not make a node with an error (e.g., an invalid custom function node) generate a similar warning in Node Settings.

For when the checks inevitably get erased (due to resolving changelog conflicts):
PR ShaderGraph on trunk

---

Comments to reviewers

Notes for the reviewers you have assigned.

[github-actions]

Hi! This comment will help you figure out which jobs to run before merging your PR. The suggestions are dynamic based on what files you have changed.
Link to Yamato: https://yamato.cds.internal.unity3d.com/jobs/902-Graphics
Search for your PR branch using the sidebar on the left, then add the following segment(s) to the end of the URL (you may need multiple tabs depending on how many packages you change)

Shader Graph
/.yamato%252Fall-shadergraph.yml%2523PR_ShaderGraph_trunk
Depending on your PR, you may also want
/.yamato%252Fall-shadergraph_builtin_foundation.yml%2523PR_ShaderGraph_BuiltIn_Foundation_trunk
/.yamato%252Fall-shadergraph_builtin_lighting.yml%2523PR_ShaderGraph_BuiltIn_Lighting_trunk

Depending on the scope of your PR, you may need to run more jobs than what has been suggested. Please speak to your lead or a Graphics SDET (#devs-graphics-automation) if you are unsure.

[Nightmask3]

Looks good to me!