Fix wrong set force translucent when devices locked

When split entering background, we will set it as force translucent
to ensure right animation when next time entering by launch adjacent.
But when devices locked, both stage invisible and we misidentify it
entering background because both stage invisible. we should avoid
do this when locked case.

Fix: 267674372
Test: manual
Test: pass existing tests
Change-Id: I9d830a5636e8dc88dfa39bb706f851b3306a8fd1