Update CS so that per-app OEM APIs can be tested

Updates to ConnectivityService so that the set OEM network preference
per app APIs can be tested via CTS.

Bug: 176496580
Bug: 176494815
Test: atest FrameworksNetTests
atest FrameworksNetIntegrationTests
atest CtsNetTestCasesLatestSdk

Original-Change: https://android-review.googlesource.com/1723050
Merged-In: I5a47dcece31749293f080af060218d827082eb67
Change-Id: I5a47dcece31749293f080af060218d827082eb67
2 files changed