[New Org/Project Creation] Add Mobile Replay Instructions

[jas-kas]

Add Mobile Replay Onboarding Instructions

• to the new org/project creation flow
• covers iOS, Android and React Native since they are GA. Flutter is excluded as it is still in beta at the time of writing this ticket
• follows same UI pattern as web projects

[getsantry]

Routing to @getsentry/product-owners-replays for triage ⏲️