Time Zone transitions are 1 tick off on Linux

Time Zone transitions are 1 tick off on Linux

When we build the AdjustmentRules up, we set the StartDate to be the Transition Time that comes from the tzfile, and we set the EndDate to the be (the next Transition Time - 1 tick). That way the next AdjustmentRule goes into effect at the exact transition time. The issue is that the code in CheckIsDst uses a less than operator when comparing the endTime, but for these rules it should be less than or equal to.

Fix https://github.com/dotnet/corefx/issues/2788.