Fix FrameworksNetIntegrationTests failure

The test is broken because CS is using
sendStickyBroadcast with all users context instead of
sendStickyBroadcastAsUser to send sticky broadcast. So update
related code on ConnectivityServiceIntegrationTest.

Bug: 178367782
Test: atest FrameworksNetIntegrationTests
      atest FrameworksNetTests
Change-Id: I7ad94fa31ea16025e6ad62d41235978f45be5d99