Notify recentTasksChanged when runningTaskAppears.

In some scenarios, like after reboot starting a task sends
onRecentTasksChanged callback and then onRunningTaskAppeared callback.
This creates a state in launcher where places that fetches tasks
depending on the onRecentTasksChanged callback to not have the correct
running tasks list.

Bug: 379145034
Test: atest RecentTasksControllerTest & manual
Flag: EXEMPT Bugfix
Change-Id: Ice355ee8e2930d9539e6e82006060abd44c64570