Thunderbird Upsell page is rendering Foundation's upsell disclaimer

[danielfmiranda]

Describe the bug

When a user makes a donation greater than $20 USD on the Thunderbird site and gets redirected to the "Upsell" page, the page renders the Foundation's disclaimer:

The expected copy is:

I authorize MZLA Technologies Corporation to automatically charge my card every month in the amount indicated above, 
starting next month on the same date as today, and continuing each month afterwards until I cancel. I understand that I must 
cancel at least 5 days before the next scheduled donation by submitting this form, and that I may only request a refund within 
15 days from the date of a donation.

This copy is actually already in the code base in thunderbird/templates/card_upsell.html:

{% block form_authorization %}
    {% blocktrans with help_url='/help' %}I authorize MZLA Technologies Corporation to automatically charge my card every month in the amount indicated above, starting next month on the same date as today, and continuing each month afterwards until I cancel. I understand that I must cancel at least 5 days before the next scheduled donation by <a href="{{help_url}}">submitting this form</a>, and that I may only request a refund within 15 days from the date of a donation.{% endblocktrans %}
{% endblock %}

However, it appears that the block form_authorization is not being defined on the template card_upsell_master.html, meaning that the text override never takes place.

To Reproduce

Steps to reproduce the behavior:

1. Go to https://thunderbird-donate.mofostaging.net
2. Make a donation greater than $20 USD
3. Once redirected to the Upsell page, note the copy is referencing the Mozilla Foundation.

Expected behavior

The copy underneath the upsell form should reference MZLA.

[cdanfon]

Hey @mtdenton can you please QA this ticket?

[danielfmiranda]

Steps to test:

1. Log into https://thunderbird-donate.mofostaging.net/admin/

2. Click "Settings" -> "Feature Flags" -> Check the "Enable Upsell View" Checkbox

3. Visit https://thunderbird-donate.mofostaging.net/en-US/, and make a credit card donation > $20 USD using the credit card information below.

4. After the donation is complete, the site should now redirect you to the "Upsell View".

5. The upsell form should have the following copy:

6. If the copy looks as expected, testing is complete!

Test Credit Card Information: Card Number: 4111 1111 1111 1111 EXP: 11/23 CVV: 123

[mtdenton]

LGTM!