Fix Pocket setting l10

[cndouglas]

• 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 #7450

Test Plan: (requires up-to-date translations)

1. Change to a language (Preferences > General > Language) with a up-to-date translation for enableExtension (see en-US/preferences.properties for an example).
2. Open Preferences > Advanced.
3. Find the setting Enable Pocket under Extensions.
4. Make sure the setting matches "Pocket" exactly and is not translated.

[cndouglas]

I made a mess, let me try again.