Modernize Compose API example project

[anandwana001]

Summary

• Update the Compose API example project to the current Android/Kotlin/Compose toolchain.
• Add edge-to-edge/IME handling, app bar accessibility labels, and a Compose navigation smoke test.
• Replace deprecated Compose lifecycle imports and Material divider usage, and clean up PiP lifecycle state handling.
• Add an AGP 9 workaround for Agora RTC 4.6.3 split AARs sharing the io.agora.rtc namespace.

Validation

• ./gradlew assembleDebug
• ./gradlew test

Notes

• Agora RTC 4.6.3 still emits a duplicate namespace warning under AGP 9. The build keeps android.uniquePackageNames=false until Agora publishes split artifacts with unique namespaces.