Anticipate technical debt and follow what Google recommends. In few words, use Kotlin and Compose.

However you should really have a look on Google guidelines. In more worlds:

• by default Kotlin and Compose
• if some logic to share between other projects in other environments: Kotlin Multi Platform (KMP)
• if shared UI: Flutter (but Google reduced Flutter teams and KMP is being better and better, so we can suppose Flutter will join the Google Graveyard