Make keyguard exit animation to remote animation.

The change is disabled by default. To enable remote animation, one needs
to set a property and to restart the WMS.

% adb root
% adb shell setprop persist.wm.enable_remote_keyguard_animation 1
% adb reboot

Test: Existing tests pass.
Bug: 175686676
Bug: 179122467
Exempt-From-Owner-Approval: The owner already gave +2 on the exactly same CL.
Change-Id: I3054ce4bbb296f09ab8bc12595f2ad17b32db7b4