Launch app intent after unlock

While the taskview may embed a showWhenLocked activity, there is no
guarantee that launching the full activity will also have this
property. Instead, prompt for auth before launching the full intent.

Fixes: 232954894
Test: manual - use showWhenLocked activity over lockscreen, then click
top right button to launch full screen

Change-Id: I82857e4cf16b90a2e1a89b61e30aa89948072f87