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