Fix Taskbar offset in launcher

This cl includes: adding support to stash controller to get device locked state. Use different taskbar offset before and after lock screen.

Test: Manual
Bug: 407589216
Flag: EXEMPT bugfix
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:cef287164f798e3daef35d9a77a679df2cd8a09d)
Merged-In: I55b27d39049458c741efc9bec365cdbc27d4e012
Change-Id: I55b27d39049458c741efc9bec365cdbc27d4e012