Add Gradle test for additional kapt arguments

libraries/examples/annotation-processor-example/src/main/kotlin/example/ExampleAnnotationProcessor.kt

@@ -11,6 +11,7 @@ public class ExampleAnnotationProcessor : AbstractProcessor() {
 
     private companion object {
         val ANNOTATION_FQ_NAME = javaClass<ExampleAnnotation>().getCanonicalName()
+        val SUFFIX_OPTION = "suffix"
     }
 
     override fun process(annotations: MutableSet<out TypeElement>?, roundEnv: RoundEnvironment): Boolean {
@@ -19,9 +20,11 @@ public class ExampleAnnotationProcessor : AbstractProcessor() {
         val elementUtils = processingEnv.getElementUtils()
         val filer = processingEnv.getFiler()
 
+        val generatedFileSuffix = processingEnv.getOptions().get(SUFFIX_OPTION) ?: "Generated"
+
         for (element in elements) {
             val packageName = elementUtils.getPackageOf(element).getQualifiedName().toString()
-            val className = element.getSimpleName().toString().capitalize() + "Generated"
+            val className = element.getSimpleName().toString().capitalize() + generatedFileSuffix
 
             filer.createSourceFile(className).openWriter().use { with(it) {
                 appendln("package $packageName;")
@@ -36,4 +39,6 @@ public class ExampleAnnotationProcessor : AbstractProcessor() {
     override fun getSupportedSourceVersion() = SourceVersion.RELEASE_6
 
     override fun getSupportedAnnotationTypes() = setOf(ANNOTATION_FQ_NAME)
+
+    override fun getSupportedOptions() = setOf(SUFFIX_OPTION)
 }