Add null check for recents when tapping on Taskbar icons

Fixes: 270669636
Test: Couldn't repro, but visually we have checks for
recentsView != null && OTHER_CONDITION, but in the else
case we don't check if recentsView being null is the reason
the if-block didn't get triggered

Change-Id: I72e7480bac56c7e7b7edb73edac4309e9923d302