Only show Condtionals when the feature flag is on.

We plan to deprecate Settings Conditionals as it seems
duplicated with quick settings. For now, we set the default
value of this flag to false to disalbe it. OEMs could still
enalbe this feature by setting the flag on.

Bug: 142927361
Test: robotests
Change-Id: Ifaf710caf0045cb185b3a8c3b04f1ce537f67896