fix(locale): Update locale switcher to use footer correctly

[vbudhram]

Because

• We don't wnt the locale switcher to overlap other components

This pull request

• Updates the footer css to not overlap, matches what we have in settings footer

Issue that this pull request solves

Closes: https://mozilla-hub.atlassian.net/browse/FXA-12734
Closes: https://mozilla-hub.atlassian.net/browse/FXA-12757

Checklist

• My commit is GPG signed.
• If applicable, I have modified or added tests which pass locally.
• I have added necessary documentation (if appropriate).
• I have verified that my changes render correctly in RTL (if appropriate).

Screenshots (Optional)