Update allowed on restricted networks getter/setter

As API review feedback, setting allowed on restricted networks
should be by uid instead of package name for security reason.
Thus, update the getter/setter to return/accept set of uids.

Bug: 188085693
Test: atest FrameworksNetTests
Merged-In: I979bf98075e6c9c0ed7e891582843fddb62643cb

Change-Id: I979bf98075e6c9c0ed7e891582843fddb62643cb
4 files changed