Introduce a flag to let app get global insets state

A new hidden flag is introduced to layout params to let system UI
components get the global insets state regardless of the z-order. That
is necessary to let components like power menu and system UI dialog.

Test: atest InsetsStateControllerTest
Bug: 178420426
Bug: 178115003
Change-Id: Ib103639ff00bf15919796788c0ba323aba0b4b4a