Follow the Android Kotlin Style Guide from Google with minimal deviations.
ktlint is used to enforce style checks. It supports a large subset of the official coding guidelines, but aspires to support the complete set. When the android style guide is unclear, fall back to the Kotlin Guidelines.
Be sure to use the Android CLI flag when running ktlint on Android code.
Android Lint is generally more concerned with semantic issues than syntactic issues. It's recommended for CI builds. Faithlife's Android Lint ruleset specifies additional rules and is extendable to enforce house rules.