Fix Demo app crash (PayPalMessages dependency)

[scannillo]

JIRA: DTMOBILES-702

Summary

The demo app currently crashes when running on device. It crashes with the following:

dyld[2527]: Library not loaded: @rpath/PayPalMessages.framework/PayPalMessages
  Referenced from: <13BF88A7-5934-34EF-B939-0432239ADD13> /private/var/containers/Bundle/Application/64E0AE18-8E3E-4B36-99E5-04C5A34A0029/Demo.app/Frameworks/BraintreePayPalMessaging.framework/BraintreePayPalMessaging
  Reason: tried: '/usr/lib/swift/PayPalMessages.framework/PayPalMessages' (errno=2, not in dyld cache), '/private/preboot/Cryptexes/OS/usr/lib/swift/PayPalMessages.framework/PayPalMessages' (errno=2), '/private/var/containers/Bundle/Application/64E0AE18-8E3E-4B36-99E5-04C5A34A0029/Demo.app/Frameworks/PayPalMessages.framework/PayPalMessages' (errno=2), '/private/var/containers/Bundle/Application/64E0AE18-8E3E-4B36-99E5-04C5A34A0029/Demo.app/Frameworks/BraintreePayPalMessaging.framework/Frameworks/PayPalMessages.framework/PayPalMessages' (errno=2), '/usr/lib/swift/PayPalMessages.framework/PayPalMessages' (errno=2, not in dyld cache), '/private/preboot/Cryptexes/OS/usr/lib/swift/PayPalMessages.framework/PayPalMessages' (errno=2), '/private/var/containers/Bundle/Application/64E0AE18-8E3E-4B36-99E5-04C5A34A0029/Demo.app/Frameworks/PayPalMessages.framework/PayPalMessages' (errno=2), '/private/var/containers/Bundle/Application/64E0AE18-8E3E-4B36-99E5-04C5A34A0029/Demo.app/Frameworks/PayPalMessages.framework/PayPalMessages' (errno=2), '/usr/lib/swift/PayPalMessages.framework/PayPalMessages' (errno=2, not in dyld cache), '/private/preboot/Cryptexes/OS/usr/lib/swift/PayPalMessages.framework/PayPalMessages' (errno=2), '/private/var/containers/Bundle/Application/64E0AE18-8E3E-4B36-99E5-04C5A34A0029/Demo.app/Frameworks/PayPalMessages.framework/PayPalMessages' (errno=2), '/private/var/containers/Bundle/Application/64E0AE18-8E3E-4B36-99E5-04C5A34A0029/Demo.app/Frameworks/PayPalMessages.framework/PayPalMessages' (errno=2), '/private/preboot/Cryptexes/OS@rpath/PayPalMessages.framework/PayPalMessages' (errno=2), '/usr/lib/swift/PayPalMessages.framework/PayPalMessages' (errno=2, not in dyld cache), '/private/preboot/Cryptexes/OS/usr/lib/swift/PayPalMessages.framework/PayPalMessages' (errno=2), '/private/var/containers/Bundle/Application/64E0AE18-8E3E-4B36-99E5-04C5A34A0029/Demo.app/Frameworks/PayPalMessages.framework/PayPalMessages' (errno=2), '/private/var/containers/Bundle/Application/64E0AE18-8E3E-4B36-99E5-04C5A34A0029/Demo.app/Frameworks/BraintreePayPalMessaging.framework/Frameworks/PayPalMessages.framework/PayPalMessages' (errno=2), '/usr/lib/swift/PayPalMessages.framework/PayPalMessages' (errno=2, not in dyld cache), '/private/preboot/Cryptexes/OS/usr/lib/swift/PayPalMessages.framework/PayPalMessages' (errno=2), '/private/var/containers/Bundle/Application/64E0AE18-8E3E-4B36-99E5-04C5A34A0029/Demo.app/Frameworks/PayPalMessages.framework/PayPalMessages' (errno=2), '/private/var/containers/Bundle/Application/64E0AE18-8E3E-4B36-99E5-04C5A34A0029/Demo.app/Frameworks/PayPalMessages.framework/PayPalMessages' (errno=2), '/usr/lib/swift/PayPalMessages.framework/PayPalMessages' (errno=2, not in dyld cache), '/private/preboot/Cryptexes/OS/usr/lib/swift/PayPalMessages.framework/PayPalMessages' (errno=2), '/private/var/containers/Bundle/Application/64E0AE18-8E3E-4B36-99E5-04C5A34A0029/Demo.app/Frameworks/PayPalMessages.framework/PayPalMessages' (errno=2), '/private/var/containers/Bundle/Application/64E0AE18-8E3E-4B36-99E5-04C5A34A0029/Demo.app/Frameworks/PayPalMessages.framework/PayPalMessages' (errno=2)

Changes

• Add PayPalMessages SPM package as direct dependency to Demo app
  • Note: This is not ideal since the dependency is already included in our BraintreePayPalMessaging wrapper target. This is a current/known limitation of our xcworkspace setup. See this PR Add PayPalCheckout to Demo App - Required to Run on Device #1170 for a full description.

Checklist

• Added a changelog entry

Authors

@scannillo

[KunJeongPark]

I think this is same item that was attached as one of the AC to Rich's PR - #1327

[scannillo]

Covered in #1327