fixed problem with source sets for java code

gradle/plugins/src/main/java/apigen/ApiGeneratorAndroidPlugin.kt

@@ -3,6 +3,7 @@ package apigen
 import com.android.build.gradle.AppExtension
 import com.android.build.gradle.LibraryExtension
 import org.gradle.api.Project
+import org.gradle.api.tasks.compile.JavaCompile
 import org.gradle.kotlin.dsl.findByType
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
@@ -34,6 +35,12 @@ class ApiGeneratorAndroidPlugin : ApiGeneratorPlugin() {
                         .forEach {
                             it.source(outputDir)
                         }
+
+                tasks
+                        .filterIsInstance<JavaCompile>()
+                        .forEach {
+                            it.source(outputDir)
+                        }
             }
         }
     }