mapper-processor: record annotation warning fix

Java duplicates the annotation on the record's field to the corresponding
getter method as well.

This results in generating the warning when using records and exclusive field annotations.
This commit fixes the issue, so the compilation warning message is
not printed for records.

mapper-processor/src/main/java/com/datastax/oss/driver/internal/mapper/processor/entity/DefaultEntityFactory.java

@@ -510,15 +510,18 @@ private Optional<PropertyStrategy> getPropertyStrategy(Set<TypeElement> typeHier
 
   private void reportMultipleAnnotationError(
       Element element, Class<? extends Annotation> a0, Class<? extends Annotation> a1) {
-    if (a0 == a1) {
+    // A hack to prevent displaying warning messages when annotating record's fields.
+    // See: https://github.com/scylladb/java-driver/issues/246
+    boolean isParentRecord = element.getEnclosingElement().getKind().name().equals("RECORD");
+    if (a0 == a1 && !isParentRecord) {
       context
           .getMessager()
           .warn(
               element,
               "@%s should be used either on the field or the getter, but not both. "
                   + "The annotation on this field will be ignored.",
               a0.getSimpleName());
-    } else {
+    } else if (a0 != a1) {
       context
           .getMessager()
           .error(