Add dev option override flag to connected display cursor flag

Adding the dev option flag that guards the dev option UI before checking
the override value. We will fall back to connected displays cursor flag
if dev option override is not available.

Test: manual and presubmit
Bug: 401213103
Flag: EXEMPT only changes the flagging logic
Change-Id: Ib9fb9a66deaf1d58b36218039d1854e287be7ce5