Instead of copying the map, like OnServicesUpdate() used to do and which
was copied into buildServiceMap() to preserve semantics while creating
testcases, start with a new empty map and do deletion checking later.
The API docs say:
// ServiceTypeExternalName means a service consists of only a reference to
// an external name that kubedns or equivalent will return as a CNAME
// record, with no exposing or proxying of any pods involved.
which implies that ExternalName services should be ignored for proxy
purposes.
Automatic merge from submit-queue
Change stickyMaxAge from seconds to minutes, fixes issue #35677
**What this PR does / why we need it**: Increases the service sessionAfinity time from 180 seconds to 180 minutes for proxy mode iptables which was a bug introduced in a refactor.
**Which issue this PR fixes**: fixes#35677
**Special notes for your reviewer**:
**Release note**:
``` release-note
Fixed wrong service sessionAffinity stickiness time from 180 sec to 180 minutes in proxy mode iptables.
```
Since there is no test for the sessionAffinity feature at the moment I wanted to create one but I don't know how.
