Drop this assert

It doesn't work as written because it expects the cachedSteps map to
be the same between the call to the put and the call to getCachedStep
-- but of course another thread could have put a new policy, which
results in PolicyStepsRegistry#update being called and the cache being
cleared (in which case the second call returns null).

Author: joegallo

x-pack/plugin/ilm/src/main/java/org/elasticsearch/xpack/ilm/PolicyStepsRegistry.java

@@ -368,10 +368,6 @@ public Step getStep(final IndexMetadata indexMetadata, final Step.StepKey stepKe
         final Step s = phaseSteps.stream().filter(step -> step.getKey().equals(stepKey)).findFirst().orElse(null);
         if (s != null) {
             cachedSteps.put(indexMetadata.getIndex(), Tuple.tuple(indexMetadata, s));
-            // assert that the cache works as expected -- that is, if we put something into the cache,
-            // we should get back the same thing if we were to invoke getStep again with the same arguments
-            Step found = getCachedStep(indexMetadata, stepKey);
-            assert s == found : "policy step registry cache failed sanity check (expected [" + s + "], found [" + found + "])";
         }
         return s;
     }