Do not expose wifi slice when no permission

Prior to this cl, slice provider always exposes wifi slice
to calling package without confirming any wifi permissions.

For current solution, we will check calling package's permission state
and decide whether slice provider should expose wifi slice or not.

Because settings search is a part of settings app,
this permission checker won't be applied to settings intelligence.

Test: manual, robotest, cts
Also run manul
Bug: 178014725

Change-Id: I2770b5b43366a5aa65c7519efc4243d350a21b26