Statusbar: don't handle the lightsout views if there aren't any notifications

Change-Id: Ib7ff613617451437957cc78787037c44cf44ea3e
statusbar: harmonize all extra button animations

Three different button animations happening at different times looks crappy

Change-Id: I62bb7cd25547e202cb28b10932bb17ba511fb5c9
UsbDeviceManager: prevent NPE

Change-Id: If4ad2290a3f1595bd142cafe06402ab392a47a81