TOPIC:

it seems all lambda codes has this error on your side.
we share screen-shot of project struct to you, wish to help you:
 

Just one more note.
I solved the inner class errors, but know I'm receving a 'duplicate value for resource 'attr/labelVisibilityMode' with config ''.' error. And the class RDGridView is also with errors because it need the androidx support. I'm almost sure we had to disable that in the pass for incompatibility with other libraries

Setting the Source and Targe Compatibility seems to solve the inner class error. And the androidx error also is gone.
I'm just with the attribute error. I'm sending an attachment with the message.
Can you guys check if it's a property in the some xml file that is colliding?

RDGridView is derived from RecyclerView
it depends as:
dependencies {
    //api 'androidx.legacy:legacy-support-v4:1.0.0'
    implementation 'androidx.recyclerview:recyclerview:1.2.1'
    implementation 'com.google.android.material:material:1.5.0-alpha02'
}

i think recyclerview has also normal version that not using androidx.
example:we use androidx, because Google recommend that.

The androidx error was temporary. Probably related to the target compatibility. You can disregard.
For now, I just need help with the attr error.

we not found file: values.xml