Iot: Enable Policheck as part of build pipeline

[ericstj]

We should run Policheck on the IOT repo and fix up the things it flags. @Anipik has the info on how to set this up. It's semi-automated by arcade infra.

[Anipik]

I can help set this up but do we want it to be part of our official builds ? we stopped doing that for the runtime repo and just run those as a part of the nightly builds and release pipeline

[ericstj]

@Anipik same behavior as dotnet/runtime should be fine. cc @joperezr @krwq