WifiTracker: Check demo mode for device instead of user

Instead of checking whether or not the current user is a demo mode,
check if the device is in demo mode when gating wifi sharing options.

Bug: 198625685
Test: atest WifiTrackerLibTests SdkWifiTrackerLibTests
Change-Id: I879f239e6aa9ee8390d8613c29dff8b85593f02e
Merged-In: I879f239e6aa9ee8390d8613c29dff8b85593f02e
11 files changed