Fix invisible voice search

When 'show search bar' is disabled, you can still tap the voice
search icon's position (even though view == gone) to launch search
action.

Partial fix borrowed from 10.2 http://review.cyanogenmod.org/#/c/21584

PS2: Use available variables instead of changing one to protected
PS3: Fix mis-paste

Change-Id: I268d0e1108992028fd324d42e7dc8b6e11c757eb