Aligned Flash info icons

[luixxiul]

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Ran git rebase -i to squash commits (if needed).

Fixes #5760

Auditors: @bbondy

Test Plan: Open about:preferences#security and make sure the info icons are aligned

[bbondy]

++

[luixxiul]

labelled QA/no qa needed since the fix was redone with #6138

[luixxiul]

I removed the milestone based on the comment above