New July Privacy Pro promotion for new installs

[amddg44]

Task: https://app.asana.com/0/1207619243206445/1207546055898910/f

This PR enables a Privacy Pro promotion for new installs

Testing Steps:

1. Update RemoteMessagingClient to use the staging URL from the comments below as the debug URL
2. Drag in BSK so that local code changes can be made. In RemoteMessagingConfigProcessor.swift update shouldProcessConfig to always return true
3. Ensure the device you are testing on has the locale region set to the US
4. Sign out of Privacy Pro (if already signed in)
5. Test that the install date range is working by overriding daysSinceInstall value (search for line case let matchingAttribute as DaysSinceInstalledMatchingAttribute in UserAttributeMatcher.swift) to test the range. Try it with 0, 4, and 12, and check that the message only appears for the 4 case
6. Sign in to Privacy Pro and confirm the message no longer appears
7. Finally, sign back out and confirm clicking the link takes you to the Privacy Pro sign up flow

[github-actions]

Your PR is hosted at https://staticcdn.duckduckgo.com/remotemessaging/config/staging/pre/ios-config.json

[samsymons]

LGTM! Tested various configurations of the desired parameters, including making sure that the message shows up for eligible users who don't already have an account, and that it does not appear for ineligible users or those who are eligible but are already signed in. I also tested that the action works as expected.

This PR had merge conflicts with a prior PR, so I've resolved those in order to get the correct value deployed to staging as part of testing - hope that's okay!