Quickstep onboarding backward compatibility for devices release with Android N & O.

Quickstep introduces swipe up gesture to open Overview and removes the
Recents button. We still want to show shelf bounce animation for Android
N & O users with Recents button because Overview is updated and swiping
up from there takes users to All Apps.

Test: manual test
Change-Id: I917c91564c47c78d2dc3883b8a7bf7824b5f5bc8
Fixes: 78647939