Left-align interactive sound indicator

[jonathansampson]

Test Plan

1. Go to a YouTube video
2. Click/toggle the tab mute button
3. Button should not jump around

Description

• 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).

Resolves #8041

[jonathansampson]

@cezaraugusto The only other symbol icon I can see is the loading icon. But this doesn't appear to impact that negatively, so I opted not to make a special-case handling for the sound icon. If you find that this fix does negatively impact the loading icon, we can do the special-case handling instead.

[cezaraugusto]

it's used for the partitioned tab but has no impact on UI so LGTM ++ thanks