Add CTS for registerNetworkOffer

Test: android.net.NetworkProviderTest on R/S device
Bug: 189074532

Original-Change: https://android-review.googlesource.com/1731451
Merged-In: Ic3ab3c487d8a9b5a9508b59f83ae35672307b933
Change-Id: Ic3ab3c487d8a9b5a9508b59f83ae35672307b933
1 file changed