Fix flaky centos test: "when manual networks were configured with portable IP"
Fix flaky centos test: "when manual networks were configured with portable IP"

NOTE: The previous implementation compared 2 unsorted arrays for equality, and so it arbitrarily passed or failed depending on the random order of the array elements. Now it reliably compares the array's contents.

See:
- commit 259d2261ba1acdc7fec8e025e90c1227066e4dee: [GX-7134] centos test symmetry: Added missing test: "when manual networks were configured with portable IP"

cloudfoundry/bosh-agent,cloudfoundry/bosh-agent