[AllApps] NORMAL <-> ALL_APPS motion clean fixes for AOSP

- Avoids drawing on scrim when headerProtection is not enabled.
- Defines a default staggered animation for all apps scrim and content per S design guidelines

[preview attached to bug]

Bug: 191259805
Test: visual
Change-Id: I0d625c9f0caba158ff58f12a39b4f18aedead84b

src/com/android/launcher3/allapps/AllAppsContainerView.java

@@ -711,6 +711,7 @@ public class AllAppsContainerView extends SpringRelativeLayout implements DragSo
 
     @Override
     public void drawOnScrim(Canvas canvas) {
+        if (!mHeader.isHeaderProtectionSupported()) return;
         mHeaderPaint.setColor(mHeaderColor);
         mHeaderPaint.setAlpha((int) (getAlpha() * Color.alpha(mHeaderColor)));
         if (mHeaderPaint.getColor() != mScrimColor && mHeaderPaint.getColor() != 0) {