Add DisplayManager API to query if the device supports seamless refresh
rate switching

It was added as a PackageManager flag earlier. Removing from there,
because PackageManagere flags are only recommendded when applications need them to filter whether they can run on a given device.

Bug: 186189147
Test: m
Change-Id: I16475b750d223caf064c413b18851b302eb4e223
5 files changed