Add native coverage listener to integration tests

Add NativeCoverageHackInstrumentationListener to
NetworkStackCoverageTests.

This allows the coverage tests to manually trigger native coverage
collection, as a workaround for collection not being triggered
automatically by the coverage infrastructure.

Bug: 185074329
Test: atest NetworkStackCoverageTests
Change-Id: Ibfb4a85d2b503810ede56893a2306cade20d6dc1