daemon/policy: Refactor test endpoint initialization
daemon/policy: Refactor test endpoint initialization

Consolidate the initialization of the test endpoints to simplify the
core logic of individual tests.

Signed-off-by: Joe Stringer <16a9a54ddf4259952e3c118c763138e83693d7fd@cilium.io>

cilium-team/cilium,tgraf/cilium,tgraf/cilium,cilium/cilium,cilium/cilium,tgraf/cilium,cilium/cilium,tklauser/cilium,cilium/cilium,tgraf/cilium,cilium-team/cilium,tgraf/cilium,michi-covalent/cilium,michi-covalent/cilium,tklauser/cilium,tklauser/cilium,michi-covalent/cilium,cilium/cilium,michi-covalent/cilium,tklauser/cilium,tgraf/cilium,tklauser/cilium,michi-covalent/cilium