Updates headers in ops settings page

What does this MR do?

Resolves the following discussion from !17330 (merged):

• @andr3 started a discussion:

  Sidenote: All the headings in this page seem off, since there is no h3, only an h2.

  For consistency, I'd leave this. But at certain point it would be good to correct all headings in this page to be h3.

  

Does this MR meet the acceptance criteria?

Conformity

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