Revert^3 "Delay start of bootanimation until after the Runtime APEX is mounted."

This reverts commit a6bb8916.

Bootanim doesn't need to be delayed because the APEXes from the system partition are now
activated very early in the boot sequence (far before bootanim is started).

See https://android-review.googlesource.com/q/topic:%22apex_earlymount_base%22+(status:open%20OR%20status:merged)

Bug: 125549215
Test: bootanim is started without being delayed
Change-Id: I367b1a5c6bf08dad770cd2bf7f6d67dbf1a813e6