Pass pod names as env var in deployments for logging purposes

[Ali Ok]

Problem
With knative/pkg#1714, pod names passed as env vars are used in logging.

Persona:
Which persona is this feature for?

Exit Criteria
Pod name passed as env vars properly to pods in deployments.

Time Estimate (optional):
0.125

Additional context (optional)
Ref impl: knative/eventing#4072