Add 'Stay unlocked on fold' toogle to settings

Added 'Stay unlocked on fold' toogle to display settings. Enabling this
setting will allow user to keep their device awake after the fold the
device.

Test: atest StayAwakeOnFoldPreferenceControllerTest LogicalDisplayMapperTest
Test: manual
  Built and flashed foldable device and manually tested by
    1. unfolded device -> enable setting -> folded device
    2. unfolded device -> disabled setting -> folded devices
  Built and flashed non-foldable device and manually tested by
    1. Went to Settings -> display -> the toogle setting is not visible
Bug: 274447767
Change-Id: I09915082b759c235811fc143184a19e2b84f1c8e