[NO ISSUE][RT] Remove runtime from ActiveManager after it stops

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

Details:
The runtime should not be removed before it's fully stopped. This may
causes issues when downstream operators need to access runtime during
shutdown.

Change-Id: I07c6398f46d4bb6d29b270aa71dee36e0d0917ae
Reviewed-on: https://asterix-gerrit.ics.uci.edu/2494
Sonar-Qube: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Contrib: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Integration-Tests: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: abdullah alamoudi <bamousaa@gmail.com>
diff --git a/asterixdb/asterix-active/src/main/java/org/apache/asterix/active/ActiveManager.java b/asterixdb/asterix-active/src/main/java/org/apache/asterix/active/ActiveManager.java
index bb76204..2aebc59 100644
--- a/asterixdb/asterix-active/src/main/java/org/apache/asterix/active/ActiveManager.java
+++ b/asterixdb/asterix-active/src/main/java/org/apache/asterix/active/ActiveManager.java
@@ -178,7 +178,7 @@
 
     private void stopIfRunning(ActiveRuntimeId runtimeId, IActiveRuntime runtime)
             throws HyracksDataException, InterruptedException {
-        if (runtimes.remove(runtimeId) != null) {
+        if (runtimes.containsKey(runtimeId)) {
             runtime.stop();
         } else {
             LOGGER.info("Not stopping already stopped runtime " + runtimeId);