CM Performance: Prevent cancelation of alert dialog

Change-Id: I981a1f3667e8b3e8e220c17c76db3315fd015bc4
Signed-off-by: Evan Anderson <evan1124@gmail.com>
Don't allow performance settings alert to be canceled

Change-Id: I09f16ddfe0dc40ca9b04e545dd200f9644adfe32
Signed-off-by: Evan Anderson <evan1124@gmail.com>