Fix keyguard clock view missing

Prepare a pair of clock controller since we can possibly show 2 keyguard
previews on the same screen.

Test: Manually tested that the clock is showing again
Bug: 327482989
Flag: ACONFIG com.android.systemui.migrate_clocks_to_blueprint DEVELOPMENT
Change-Id: Ic92244c86b22c1af8d80419f60b67ab9f7d4372a