[C++] reuse MyTestProvider in ProviderTest.cpp
[C++] reuse MyTestProvider in ProviderTest.cpp

Change-Id: I4dc059ae626fa2be6c059778d213114c6dccdfbe

bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr