Create ServiceConnectivityResources

Create the ServiceConnectivityResources package, which contains
resources Connectivity unbundled from platform resources.

Migrate the first few resources from ConnectivityService that have no
RRO in AOSP. To avoid boot time impact, avoid loading the resources in
the ConnectivityService constructor.

Bug: 182125649
Test: atest FrameworksNetTests
Merged-In: I77ac6f4303c54acc96f16e18ef02add30298ff3d
Change-Id: I77ac6f4303c54acc96f16e18ef02add30298ff3d