Fix EventActivityIdControl test on MonoVM. (#39178)

Fix EventActivityIdControl test on MonoVM. (#39178)

Make EventSource call static version of EventActivityIdControl in
EventPipeEventProvider instead of direct calling low level
EventPipeInternal (now only called from EventPipe* sources). Doing
it that way will also keep EventPipeEventProvider.EventActivityIdControl
in S.P.C meaning that tests like eventactivityidcontrol won't risk
of using methods that has been trimmed away by linker.

Added missing case into Mono's EventPipeInternal::EventActivityIdControl
implementations.

Enabled eventactivityidcontrol test on Mono runtime. Adjusted test to
use static EventPipeEventProvider.EventActivityIdControl version.