Add cancel test cases for async DNS API

Bug: 124882626
Test: built, flashed, booted
      atest DnsResolverTest

Change-Id: I9b496821e422f71009319eeefc6f3c6c1e249111
1 file changed
tree: 46bc551935323e0db29b06cd7657d31458b8ce30
  1. tests/