Remove locked user tasks if starting overlay fails

This is a more graceful failure case than giving up and just letting
the task show unmodified on the screen if something goes wrong.

Test: runtest -x WorkLockActivityControllerTest.java
Bug: 31001762
Fix: 31064912
Change-Id: I505c00f411f41fb927c31d2280bdeda69e15b4d4
2 files changed