Updated demo app with `.userAction`

[stechiu]

Updated demo app with BTPayPalVaultRequest.userAction = .setupNow

Summary of changes

• Passed in BTPayPalVaultRequest.userAction = .setupNow. Must use "ModXO (New PayPal Checkout) Tokenization Key" to see the PayPal button changes
• Removed .userPhoneNumber which was causing 422 error
• Updated new PayPal Checkout toggle and tokenization names for clarification

Checklist

• [ ] Added a changelog entry
• [ ] Tested and confirmed payment flows affected by this change are functioning as expected

Authors

List GitHub usernames for everyone who contributed to this pull request.

• @stechiu