[Overview Actions] Change actions view UI based on different nav modes.

1. Change the overview actions container to 66dp height.
2. For 3 button mode, container will have 8dp bottom margin.
3. For gesture mode, container will have 16dp bottom margin.
4. Action buttons and close button will always be in the center vertically.

Spec: https://docs.google.com/presentation/d/1gXWNdCRXvXuEhgDmE0TX2KYqCxIQBXVtWKdl4pKrno8/edit#slide=id.g840c32b190_3_6

Demo:
- 3 button: https://screenshot.googleplex.com/2Y3uMaJMi9E
- gesture: https://screenshot.googleplex.com/XzaKHpp5ke9
Test: tested for both modes and when switch between.
Bug: 155444592

Change-Id: If66d369df0218b7ee2abab8a3f345488bf223b16