Wire display context for text toasts

Toast doesn't work correctly for multi-display. When default display's
screen off, the toast wouldn't be able to show on secondary display.
Without this change, default display screen state will cause text toasts
doesn't correctly show up.

Bug: 233717651
Test: atest ToastUITest
Change-Id: I1705bc71062fa28c378bf7cc02d104c0f53ce865