pkg/endpoint: log what caused policy changes
pkg/endpoint: log what caused policy changes

Before this commit, we only logged whether policy was changed or not for a given
endpoint or consumable, not what caused the policy change itself. To get more
visibility into what might trigger regenerations, log at debug level what causes
policy changes.

Signed-off by: Ian Vernon <ian@cilium.io>

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