Handle unstable sort in test for cell-to-point connectivity.
The parallel implementation in CellSetExplicit that builds cell-to-point connectivity from point-to-cell connectivity uses a parallel sort-by- key. The sort-by-key in the device adapter is not guaranteed to be stable, so values associated with a particular key can be in any order. The test for the result was expecting the connectivity array to be in a particular order. Change the test to allow any connectivity ordering that is still valid.