[IS-05-02] test_07 and test_08 activate and enable receivers without staging a transport file

[garethsb]

These two test cases make activations which set up some transport_params and set master_enable to true, in order to check that the IS-04 subscription (which reflects the IS-05 /active endpoint) is updated.

However, they don't stage a transport_file. Is it reasonable to expect an RTP receiver to assume default media format-specific parameters, etc. in this case?

Note that IS-05-01 test_26 "Immediate activation of a receiver is possible" tests activation WITHOUT setting master_enable to true, whereas the equivalent test for Senders (test_25) does set master_enable to true, suggesting that this problem is recognized in that test suite.