Exempt VAMC System VA Police content type from the outdated content report and trigger

[xiongjaneg]

User Story or Problem Statement

As a VAMC editor, I don't want to get outdated content reports for the VAMC System VA Police page that I won't be able to edit initially.

Initially, the VAMC System VA Police page won't have any fields that are editable by local editors. Therefore, we don't want outdated content reporting to include this page and alert editors since they can't do anything to it.

Acceptance Criteria

• [ ] Add the content type to the getExcludedContentTypes() in va_gov_notifications
• [ ] Remove content type from the exposed filter on the outdated content report View.

[swirtSJW]

@xiongjaneg I don't think we should frame this toward the MVP. It would be a year or more before this page would ever show on anything related to outdated content. We should look toward a bit farther out in our decision.