Exclude theme review from anything policy-review-selection related

[eviljeff]

Fixes mozilla/addons#16321

Description

Makes approve and reject reviewer actions available to theme review again, by making a blanket exclusion of policy review selection actions for themes.

Context

Previously we had a(n increasingly complicated) set of criteria for determining if a reviewer action should be available when enable-policy-review-selection was enabled, and was disabled. Themes were supposed to be excluded from the changes, but one of the patches introduced a regression.

Theme review will eventually switch over to use policy-review-selection too, but not at launch (and some issues like mozilla/addons#16261 need to be done too)

Testing

• enable waffle switch 'enable-policy-review-selection`
• navigate to the review page for the theme
  • if you don't already have a theme, upload a theme (upload an xpi or use the theme wizard)
• see approve and reject actions are available for themes

Checklist

• Add #ISSUENUM at the top of your PR to an existing open issue in the mozilla/addons repository.
• Successfully verified the change locally.
• The change is covered by automated tests, or otherwise indicated why doing so is unnecessary/impossible.
• Add before and after screenshots (Only for changes that impact the UI).
• Add or update relevant docs reflecting the changes made.