Remove ServiceDiscoveryClient* from PrivetHTTPAsynchronousFactoryImpl interface
PrivetHTTPAsynchronousFactoryImpl can use ServiceDiscoverySharedClient::GetInstance.
Also we don't use this for testing, so we can simplify interface.
BUG=
461504
Committed:
https://crrev.com/e61a6220ca4341f7eafac6dc3aacaa6f80a89896
Cr-Commit-Position: refs/heads/master@{#318013}