Remove "scan" and "a" word from New Policy page actions

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What does this MR do and why?

This MR removes the "a" and "scan" word when container scanning or dependency scanning is selected from the actions dropdown in the New Policy page

Related issue: #464720

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Select a project
2. On left side nav, select "Secure < Policies"
3. Click "New Policy"
4. Select "Scan execution policy"
5. Scroll down to "Actions" section
6. Change the selection dropdown to "Container Scanning" or "Dependency Scanning"
7. It should remove the "a" and "scan" word in the sentence

Related to #464720