Changed 'ConstantEndpointDetector' to have value semantics.
Changed 'ConstantEndpointDetector' to have value semantics.

The class 'ConstantEndpointDetector' was holding a reference to one of
its constructor parameters which introduces unnecessary brittleness.

In this patch we adjust the class to just hold a copy of the
originally passed value instead.

Review: https://reviews.apache.org/r/64805/

abudnik/mesos,asamerh4/mesos,kaysoky/mesos,andschwa/mesos,Gilbert88/mesos,asamerh4/mesos,asamerh4/mesos,kaysoky/mesos,Gilbert88/mesos,andschwa/mesos,gsantovena/mesos,andschwa/mesos,gsantovena/mesos,reneploetz/mesos,dforsyth/mesos,asamerh4/mesos,gsantovena/mesos,asamerh4/mesos,kaysoky/mesos,chhsia0/mesos,jpeach/mesos,dforsyth/mesos,abudnik/mesos,jpeach/mesos,reneploetz/mesos,dforsyth/mesos,kaysoky/mesos,jpeach/mesos,kaysoky/mesos,dforsyth/mesos,andschwa/mesos,andschwa/mesos,chhsia0/mesos,asamerh4/mesos,chhsia0/mesos,chhsia0/mesos,gsantovena/mesos,dforsyth/mesos,kaysoky/mesos,Gilbert88/mesos,jpeach/mesos,jpeach/mesos,gsantovena/mesos,gsantovena/mesos,Gilbert88/mesos,abudnik/mesos,andschwa/mesos,Gilbert88/mesos,jpeach/mesos,reneploetz/mesos,abudnik/mesos,abudnik/mesos,reneploetz/mesos,gsantovena/mesos,jpeach/mesos,asamerh4/mesos,dforsyth/mesos,reneploetz/mesos,chhsia0/mesos,abudnik/mesos,kaysoky/mesos,andschwa/mesos,chhsia0/mesos,dforsyth/mesos,Gilbert88/mesos,Gilbert88/mesos,reneploetz/mesos,abudnik/mesos,chhsia0/mesos,reneploetz/mesos