Remove usage of Context.NETWORK_STACK_SERVICE

The NetworkStack.getService() API should be used instead.

Bug: 151243982
Test: atest FrameworksNetTests TetheringTests
      Manual tethering test
Change-Id: I7855090bffbe895c8349ad4903b8f2eb55515f0b
1 file changed
tree: 6f6b0f2d7216703fbeea1aff82e2f0fec50a16d1
  1. core/
  2. services/
  3. tests/