WifiSetup: If device has Leanback feature specify tv.settings

Fugu has both com.android.settings and com.android.tv.settings so
currently it brings up a selector dialog for how to handle the wifi
intent, which leads to "Activity is launching as a new task, so
cancelling activity result." Fix this by passing the component name
in the intent if FEATURE_LEANBACK is present

Change-Id: I470590315d3f95a32b7796dd4a916a543392fcd6