MSC_Tests: Make sure only sgsap related tests use the SGs interface

At the moment the SGs interface is started and connected in all tests in
the testsuite. This may be a problem because the IUT may lack the SGs
support. In this case all tests would fail because of the missing SGs
interface.

Lets initalize and connect the SGs interface only for SGs related tests
to prevent unrelated test failures.

Change-Id: I8e012e3599ad00db2e132b6463499f8a4a2307f1
Related: OS#3614
1 file changed