Ensure not in demo mode when setting global settings.

Test: atest CtsDevicePolicyTestCases
Fixes: 236017272
Change-Id: I0f73b60d3d36d4d4a4cb531c0955055e3abe3f06
Merged-In: I0f73b60d3d36d4d4a4cb531c0955055e3abe3f06
7 files changed