Respect the config var exported by WikimediaEvents that, if set to true,
forces oversampling. When oversampling, all events are logged even if
they would have been sampled out. The isOversample property is set to
true if the event was oversampled and would not otherwise have been
logged.
Bug: T206543
Depends-On: I5fdf5fdd2dc0d99a0a0d7eb7ab2e3dce4798009b
Change-Id: I7e504884a888c4d080cd4762549b72489126ed65