Fix actions view showing up when it shouldn't in a couple spots

- Replace HIDDEN_FULLSCREEN_PROGRESS with INDEX_FULLSCREEN_ALPHA
- When animating actions in after swiping to overview from an app,
  start at alpha 0 (since we setState(OVERVIEW) without animation
  when we settle, meaning alpha would already be 1).
- Fade in actions at the same duration as the icon scale when
  entering overview from an app
- Hide actions during quick switch from home

Tests:
- Start quick switch from home and swipe up back to home
- Start quick switch from home and swipe up to overview
- Go to overview from home
- Go to overview from an app
Verify actions don't appear on the first, and fade in
for the rest.

Bug: 157597385
Change-Id: I43a0be702066f91e13ce2a720278aae27160c557