it can happen that there are multiple slices, and some of them
outdated, so we relax the test to check that at least one
has the corresponding fields mirrored.
Add support to the endpoint slice mirroring controller to mirror
annotations, in addition to labels, but don´t mirror endpoint
triggertime annotation.
Also, fix a bug in the endpointslice mirroring controller, that
wasn't updating the mirrored slice with the new labels, in case
that only the endpoint labels were modified.
This test was trying to create an Endpoints resource that the Endpoints
controller would also attempt to create. This could result in a failure
if the Endpoints controller created the resource before the test did.
