Correct network-traffic mapping for elasticsearch

[cmadam]

Describe the bug

Some mappings for network traffic in the elastic ECS connector are incorrect - they use network_traffic instead of network-traffic. Because of this, sometimes STIX-shifter does not return any results when we are querying for network traffic.

To Reproduce
Steps to reproduce the behavior:

1. Bring up an instance of Elasticsearch
2. Import in this instance the (index win-111-winlogbeat-bh22-20220727
3. Run the following STIX query against this index:

   [network-traffic:src_port = 50383] START t'2022-07-27T00:00:00Z' STOP t'2022-07-28T00:00:00Z'
   

4. The query will not return any results.

Expected behavior
Running the query against the index described above should have returned 1 entity.

Screenshots
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Desktop (please complete the following information):

• Ubuntu 20.04
• Python 3.8.10
• STIX-shifter version: 5.1.1

Smartphone (please complete the following information):

• N/A

Additional context
Add any other context about the problem here.