Support For Open5gs v2.2.6

• Add support for Open5gs version 2.2.6
• Update SMF config to align with the new Open5gs schema
• Add sample srsLTE config files
• Improve Pod Initialization

Support For Open5gs v2.1.7

Release is mapped to the v2.1.7 release of Open5gs.

Open5gs release note: https://open5gs.org/open5gs/release/2021/02/08/release-v2.1.7.html

Subsequent releases will be mapped to the Open5gs release cycle also