Android proto import files

Question

I am making a Flutter android application which uses photo files. First I had all definitions based in one .proto file. But now I had to split the definitions onto multiple files.

With one file my build script worked:

buildscript {
    ...

    dependencies {
        ...
        classpath 'com.google.protobuf:protobuf-gradle-plugin:0.8.17'
    }
}
...
apply plugin: 'com.google.protobuf'

android {
    ...
    sourceSets {
        main.java.srcDirs += 'src/main/kotlin'
        main.proto.srcDirs += '../../protos'
    }

    ...
}

protobuf {
    protoc {
        if (project.hasProperty('protoc_platform')) {
            artifact = "com.google.protobuf:protoc:3.18.0:${protoc_platform}"
        } else {
            artifact = "com.google.protobuf:protoc:3.18.0"
        }
    }
    generateProtoTasks {
        all().each { task ->
            task.builtins {
                java {
                    option "lite"
                }
            }
        }
    }
}

With the folder structure

project
  | - android app
    | - android
       |- build.gradle 
  | - protos
      myfile.proto

Now I have updated it to

project
  | - android app
    | - android
       |- build.gradle 
  | - protos
      |- shared
         |- dependency 
          - dependency.proto
      - myfile.proto

myfile.proto imports dependency.proto, but when I compile the android project I get the error that protos/shared/dependency/dependency.proto is not found.

How must I update the build.gradle file?