Add getDefaultFinalizerName method

Author: Soroosh Sarabadani

operator-framework/src/main/java/io/javaoperatorsdk/operator/api/ResourceController.java

@@ -28,4 +28,10 @@ public interface ResourceController<R extends CustomResource> {
      */
     UpdateControl<R> createOrUpdateResource(R resource, Context<R> context);
 
+    // What about we let developer to set the finalizer Name through overriding
+    // this method rather than setting it as attribute in annotation?
+    default String getDefaultFinalizerName() {
+        return this.getClass().getCanonicalName();
+    }
+
 }