RealTimeGetComponent fails for INPLACE_UPDATE when Cdcr enabled

When we were adding bi-directional sync support in CDCR ( SOLR-11003 ) we changed the CDCR Update Log codec to write an extra bits. 

When we use the RealTimeGet component on a cluster running CDCR and have in-place updates in the update log we will falsely trip an assert thus causing the request to fail

Here's the proposed change

-                 assert entry.size() == 5;
+                 if (ulog instanceof CdcrUpdateLog) {
+                   assert entry.size() == 6;
+                 }
+                 else {
+                   assert entry.size() == 5;
+                 }