[ECS] Dynamic PortMapping within a range.

ECS allows static port mapping by providing HostPort value in TaskDefinition. ECS and also allows dynamic port mapping by setting HostPort = 0.

What we want to achieve is to have the HostPort dynamically allocated within the range provided by TaskDefinition (or Service). This is very important to achieve micro-segmetation, by knowing in advance what would be the host port ranges.

Start by reviewing the ECS TaskDefinition and Service port-mapping behavior described in the issue, especially HostPort=0 and the requested range. There are no repository files or tests identified; completion means ECS can dynamically allocate HostPort values within a range supplied by the TaskDefinition or Service.

Written by the indexing model from the issue text.