Report isKnownService in discovery stop metrics

In the reportServiceDiscoveryStop function, the isKnownService
value is not set. This means that it is not possible to track
how many discovery queries are answered from cache. To track
this information, add the isKnownService to
reportServiceDiscoveryStop.

Fix: 339738663
Test: atest FrameworksNetTests NsdManagerTest
Change-Id: Idf9948826d3b8ffff9bce4f224543af87c653d80
4 files changed