Extract maximum amount + speedbump index from NIC

Flag: ACONFIG com.android.systemui.notifications_icon_container_refactor DEVELOPMENT
Fixes: 309555139
Bug: 278765923
Test: manual
  1. Verify AOD icons and overflow dot render correctly.
    a. On AOD
    b. On bypass lock screen
  2. Verify Status Bar icons and overflow dot render correctly.
  3. Verify notification shelf icons and overflow dot render correctly.
    a. In expanded shade
    b. On lock screen
Change-Id: I5a5b335708461a3921e2209c1886e0ce4d79e74b