Fixes port acquiring logic in DockerStandaloneHost

Previous code used integer keys in port map. But because
JSON doesn't support integer keys they were converted
to corresponding string representations and were not
found on subsequent deployments

Change-Id: I0477a043854a5ed78545d3b944397cdbf2352bd8
Closes-Bug: #1444681

DockerStandaloneHost/package/Classes/DockerStandaloneHost.yaml

@@ -187,24 +187,25 @@ Methods:
       - $portMap: $.getAttr(portMap, dict())
       - $applicationPorts: $.getAttr(applicationPorts, dict())
       - $key: format('{0}-{1}-{2}', $applicationPort.port, $applicationPort.protocol, $applicationName)
+
       - If: $key in $applicationPorts
         Then:
-          - Return: $applicationPorts[$key]
+          - Return: $applicationPorts.get($key)
 
-      - $port: $applicationPort.port
+      - $port: str($applicationPort.port)
       - If: $port in $portMap
         Then:
-          - $port: 1025
+          - $port: '1025'
       - While: $port in $portMap
         Do:
-          $port: $port + 1
+          - $port: str(int($port) + 1)
 
       - $portMap[$port]: $applicationName
       - $applicationPorts[$key]: $port
 
       - $.setAttr(portMap, $portMap)
       - $.setAttr(applicationPorts, $applicationPorts)
-      - Return: $port
+      - Return: int($port)
 
 
   _releaseApplicationPorts: