Enable persist.wm.debug.predictive_back_anim by default.

With this change predictive system navigation animations will be enabled
when the "Predictive Back Animation" developer option is enabled
(default off).

Progress events will also be dispatched to apps that are registering
OnBackAnimationCallbacks. This allows SysUI & Launcher animations to be
enabled in teamfood.

Bug: 238475924
Test: Turn on "Predictive back Animation" dev option. Make sure sys nav
anims show up in Settings.
Test: Turn on SysUI teamfood flags. Make sure SysUI back animations show
up.

Change-Id: I7566beb86f1f1303e7de3f1fe8acf711c919644c