Remove wgEchoMaxNotificationCount and wgEchoPollForUpdates from the
startup module and put them in the ext.echo.init module.
Change-Id: I03f9a3953aa97ead1a29c13a992a02404a6d0b68
This ensures that each repository's "npm test" command is fully
independent of wherever it might be in the filesystem.
Bug: T206485
Change-Id: I3073faa59bbb6606120f8ea52b0ebad66094d253