Add ios specific templates experiment class

What does this MR do and why?

When we know that a user is building an IOS application we should update the first time experience to guide them through set up for what is needed in order to deploy onto IOS.

This MR adds the experiment yaml, experiment class and candidate behavior for this experiment.

Part of issue: Update pipeline zero state to suggest IOS speci... (gitlab-org/growth/team-tasks#509 - closed)

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