Use consistent table columns for environment variables across security docs

Problem to solve

Currently, the Application Security docs use tables with different column ordering for displaying environment variables. For example:

• Container Scanning docs use Environment variable, Description, Default.
• Dependency Scanning docs and the rest of the Application Security docs use Environment variable, Default, Description.

Further details

Identified in !28617 (comment 324642417)

Proposal

Change the Container Scanning docs to use Environment variable, Default, Description.

Who can address the issue

Other links/references