* Add podspec to Flutter iOS framework.
Flutter iOS apps are already pod-enabled, so we might as well turn the
engine framework into a pod, so we don't have to manually copy the
current Flutter.framework into the app directory on every build, but
rather let Cocoapods wire things up for us.
For that to happen, we need a pod spec for Flutter.framework. This spec
will not be published, but rather downloaded as part of the engine
artifacts, and the app's Podfile will have a local path dependency on
it.
* Update licenses_golden...
Mikkel Nygaard Ravn
Jakob Andersen