AGENT_INJECT_VAULT_ADDR Environment Variable Logic Updates

Enhance the conditionals around the agent-injector deployments' environment variable AGENT_INJECT_VAULT_ADDR so that via the chart and BigBang we are able to explicitly set this variable and their built in logic is skipped or ignored if we set our own environment variable for AGENT_INJECT_VAULT_ADDR

If you set the extra environment variable AGENT_INJECT_VAULT_ADDR for the Injector ENVs you will encounter a helm install error due to duplicate ENVs.