Remove experiment

Signed-off-by: Ryan Nett <JNett96@gmail.com>

Author: rnett

tensorflow-core/tensorflow-core-api/src/main/java/org/tensorflow/op/CustomGradient.java

@@ -34,7 +34,7 @@
  */
 @SuppressWarnings("rawtypes")
 @FunctionalInterface
-public interface CustomGradient<T extends RawOpInputs<?>> {
+public interface CustomGradient<T extends RawOpInputs> {
 
   /**
    * Calculate the gradients for {@code op}.