Add lang parameter to terms of use update email

[suecarmol]

Description

Add lang parameter to terms of use update email.

Rationale

If you add the lang parameter, then the user will receive the email in their preferred language.

Phabricator Ticket

T286897

How Has This Been Tested?

Screenshots of your changes (if appropriate):

Types of changes

What types of changes does your code introduce? Add an x in all the boxes that apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Minor change (fix a typo, add a translation tag, add section to README, etc.)

[jsnshrmn]

👍 In the interest of being extra cautious, I (locally) created a fake german translation string, ran the translation script, and then fired this email. I checked the output and verified that my fake string was in the output. All good. Thanks!