Hide the home/up arrow in the voicemail pref screen.

The behavior doesn't work because of a more underlying problem in the
with roots in the dialog component, so hiding the arrow for L. Not
ideal, but figuring it's better than a back arrow which does nothing.

Bug: 17650972
Change-Id: Ic51795b3231f93bed175a1dcbf19eaf6c6ff3fa5
1 file changed