Spec changes for agent and loadbalancer

[ramaraosrikakulapu]

Below are the summary of changes -

Agent:

• Adding new header 'CF_INSTANCE_INDEX' for k8s environment

Loadbalancer:

• Updated access log path for load balancer
• Updated logic for replacing nginx 'server block' configuration
• Updated nginx config to allow web sockets, allow underscores and custom logs

[ramaraosrikakulapu]

@ayasuda-ge .. Can you please review the code and squash merge the changes, if everything looks good

[ramaraosrikakulapu]

@ayasuda-ge .. Can you please review the code and squash merge the changes, if all looks good. Please let me know for any questions.