Use public API of NetworkAgent in TestNetworkService

- Create NetworkAgent by using the public API of NetworkAgent.
- Remove the usage of NetworkInfo.

Bug: 172183305
Test: Build pass.
Test: atest FrameworksNetTests
Test: atest CtsNetTestCasesLatestSdk
Test: atest NetworkStackIntegrationTests
Test: atest TetheringIntegrationTests
Change-Id: Icba59295861201c221587caa9df02275c4087fb8
1 file changed
tree: 08c6bf71db3ffcfebffd4550d880108554b904e3
  1. core/
  2. services/
  3. tests/