tests are sensitive to random variable stream assignment

A number of tests are sensitive to changing the stream assignment. For example,

$ NS_GLOBAL_VALUE="RngRun=2" ./test.py -n

yields:

List of FAILed tests:
    cobalt-queue-disc
    lte-cqi-generation
    lte-x2-handover
    mobility-trace
    pie-queue-disc
List of CRASHed tests:
    lte-link-adaptation
    lte-test-deactivate-bearer

Either the test needs to be insensitive to the run number (and seed number), or these values need to be fixed to the defaults, so that any RngRun or RngSeed value passed in such as above will pass all tests. My first attempt for all of these would be to make the test insensitive, but if comparing output against a trace file, then the run number and seed should probably be set to a fixed value.

I am not proposing to extend the CI jobs (this regression testing can be done periodically on Jenkins).