NsdService: test coverage for client requests.

Adding coverage for:
  - NsdManager client disconnection
  - in-flight request GC

Test: new test passes
Bug: 37013369, 33298084
Bug: 38503832

(cherry picked from commit 4dd4db77209ab2ef302a3a2a4892b05aadd26ec6)

Change-Id: I02aca772d88306acae09db739ced7a2b1119b72b
2 files changed
tree: cabe5c7effe1e2e43c2b112ae8bc0ec3eeeae2e7
  1. core/
  2. services/
  3. wifi/