IssueTracker

Artifact used (ex. androidx.appcompat:appcompat:1.0.0-alpha1): ROOM
Version used: 1.1.0-present
Theme used: NA
Devices/Android versions reproduced on: NA build-time

- Relevant code to trigger the issue: Any kotlin data class in an external module. Building the following project can reproduce it: https://github.com/hzsweers/CatchUp

In Kotlin, data classes will have a primary constructor and sometimes generated synthetic constructors. ROOM's processor will complain about the presence of the synthetic ones (which are usually visible when reading the class file from an external library), but since it's reading metadata it could use it to find the "primary" constructor to know for sure.

Example: https://github.com/hzsweers/CatchUp/blob/6a6bee429524eb4dece065f6862d2c7ec83d65ce/tooling/moshkt/compiler/src/main/kotlin/io/sweers/moshkt/compiler/MoshKtProcessor.kt#L124

The solution would be to find that constructor, then match it to the corresponding constructor as seen in the elements API