Demo config includes too many platforms

[SimonDarksideJ]

XRTK - Mixed Reality Toolkit Bug Report

Describe the bug

When loading the examples in to a clean project, lots of errors occur related to data providers not present. At present the config only works if ALL providers are present

To Reproduce

1. Create a new XRTK project and add core/sdk
2. Import Examples
3. Create Scene using demo config (DemoMixedRealityToolkitRootProfile)

Expected behavior

Should be able to work without change using base platforms

Actual behavior

Errors