Allow Task menu to draw down to screen bottom

- Use all available spaces minus inset to draw the task menu
- Also enabled scrolling for app chi1p menu

Fix: 329271577
Bug: 326952853
Test: manual
Flag: Nonee
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:26e487c6acd86c668518d379f90cb84f3d89a486)
Merged-In: Ibdff07043f2c64495f97e11e80209bcc3f5dcb4f
Change-Id: Ibdff07043f2c64495f97e11e80209bcc3f5dcb4f