This patch is moving the navigation bar related insets logic from
DisplayPolicy to com.android.systemui.navigationbar package. To fully
match the feature, callbacks between NavigationBar and
EdgeBackGestureHandler is added to handle the nav bar button force
visible case.
Bug: 239145252
Test: DisplayPolicyInsetsTests
Test: InsetsPolicyTest DisplayPolicyTests
Test: InsetsControllerTest
Change-Id: I628a9e24df14268f2c7e92ab8ecd8d5d0d611847
070ae52e71