Check the process state for the killProcessesForRemovedTask

Upon removing tasks from the recent UI, we should check if the process
state of the target process is foreground or not, and don't kill it
if it's still in the foreground - the killing will be deferred as long
as it's falling into the background state (not perceptible anymore).

Bug: 227303045
Test: Manual
Change-Id: If2b55e5159ee3642c96f0337e82c09faaf22de10