[NO ISSUE][API] Rename Request Cancellation API Parameter

- user model changes: yes
- storage format changes: no
- interface changes: no

Details:
- Rename the parameter for the request UUID in the query
  cancellation servlet from uuid to request_id to be more
  user friendly.

Change-Id: I357762beff5384e52ce6f25837d2390f02ad10ad
Reviewed-on: https://asterix-gerrit.ics.uci.edu/3334
Sonar-Qube: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Integration-Tests: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Contrib: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Till Westmann <tillw@apache.org>
diff --git a/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/http/server/CcQueryCancellationServlet.java b/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/http/server/CcQueryCancellationServlet.java
index 370579a..00aef9e 100644
--- a/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/http/server/CcQueryCancellationServlet.java
+++ b/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/http/server/CcQueryCancellationServlet.java
@@ -39,7 +39,7 @@
  */
 public class CcQueryCancellationServlet extends AbstractServlet {
 
-    public static final String REQUEST_UUID_PARAM_NAME = "uuid";
+    public static final String REQUEST_UUID_PARAM_NAME = "request_id";
     private static final Logger LOGGER = LogManager.getLogger();
     private final ICcApplicationContext appCtx;