Upgraded preferred WPT version to Windows 10 1903
Upgraded preferred WPT version to Windows 10 1903

I've been using the 1903 version of Windows Performance Toolkit,
10.0.18362.1, since it was released. There won't be a 1909 SDK so it is
past time to start pushing 1903 as the default that comes with UIforETW.
The main change I have noticed is that adding and removing columns is
slightly nicer in this version.

ariccio/UIforETW,google/UIforETW,ariccio/UIforETW,ariccio/UIforETW,google/UIforETW,google/UIforETW,google/UIforETW,ariccio/UIforETW