Analytics audit: update free up space event

[SergioEstevao]

| 📘 Part of: # |
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Fixes #

Add the missing source parameter when sending freeUpSpaceMaybeLaterTapped and set the check to percentage back to 10% of free space instead of 100%.

To test

In order to test it easier change the check for percentage on ManageDownloadsCoordinator.shouldShowBanner to 0.1

1. Start the app fresh
2. Do some downloads of episodes
3. Go to Profile tab
4. Tap on Downloads
5. Tap on the X button
6. Check that the freeUpSpaceMaybeLaterTapped is sent and source parameter is set to downloads

Checklist

• I have considered if this change warrants user-facing release notes and have added them to CHANGELOG.md if necessary.
• I have considered adding unit tests for my changes.
• I have updated (or requested that someone edit) the spreadsheet to reflect any new or changed analytics.

[dangermattic]

	1 Warning
⚠️	This PR is assigned to the milestone 7.81 ❄️. The due date for this milestone has already passed. Please assign it to a milestone with a later deadline or check whether the release for this milestone has already been finished.

Generated by 🚫 Danger

[danielebogo]

All good!