Don't show Wi-Fi indicator until it is validated

This change makes it so that we won't show the Wi-Fi indicator in the
status bar unless it is validated. So we shouldn't ever see the
indicator with an 'x' on it

Test: atest SystemUITests; manual
Bug: 136473125
Change-Id: I14cf8dd8387a5df569f897a27ffe59bf4bdf27f8