open grid task menu to the right of icon

This makes the TaskMenuViewWithArrow open to the right of the icon if
there is enough space, and to the left if not. It also works correctly
in RTL, inverting the side to open by default.

Bug: 193432925
Test: open Overview and tap the app icon
Change-Id: Ib1098f48ed28d2e0758fb0e3fb733e86271fa1a0
5 files changed