Adding coil to sample

[KevinSchildhorn]

Summary

Adds an example of how the coil extension works in the Android app

Implementation notes

I added coil to shared and show it on Android. This is so I can prove it's KMP ready, but I don't want to overhaul the SwiftUI.

Testing

• Built the project and ran its test suite locally
• Added or updated tests covering this change
• Verified by hand

Platforms verified

• Android
• iOS [In progress]

User-facing impact

• Internal only — no API, behavior, or build configuration changes for users
• User-facing change
• Breaking change

Documentation

• Docs updated where this change affects them (README, API docs, samples)
• Agent instructions updated (CLAUDE.md / AGENTS.md), if the repo has them
• No documentation changes needed

Screenshots or recordings