pluginloadtest and sendfiletest are crashing. This patch fixes that by allowing Daemon::init() to be called from TestDaemon

## Test Plan

### Before:
Both tests are crashing because it is not able to find any devices. It is not able to find any devices because the LanLinkProvider is not being added because Daemon::init() is not being called.

### After:
pluginloadtest and sendfiletest pass