Simplify e2e-suite and remove junk. (#9184)
Simplify e2e-suite and remove junk. (#9184)

* Simplify e2e-suite and remove junk.

Removing the hardcoded list of valid e2e targets which is a maintence
overhead.

* Adding comment and fixing E2E_ARGS.

* Fix shellcheck

* Fix typo

istio/istio,geeknoid/istio,geeknoid/istio,smawson/istio,geeknoid/istio,geeknoid/istio,smawson/istio,istio/istio,smawson/istio,istio/istio,geeknoid/istio,istio/istio,smawson/istio,geeknoid/istio,smawson/istio,istio/istio,smawson/istio