Do not fail when keep alive fails

Fix logic error where we return false instead of true for the keep alive
enabling.

Kiosk apps can choose to not implement the keep alive service so it is
expected to return true even if it fails. To reflect this, I have
changed the test and the logs appropriately.

Bug: 319164524
Test: atest DeviceLockControllerRoboTests
Change-Id: If9c453ac0ade20d45bf892209dc7d280b2a57ea0
2 files changed