proc-monitor: Update window stack when updating app life cycle

proc-monitor: Update window stack when updating app life cycle

Update window stack information when app life cycle is updated
to get the latest window stack information.

Window stack is dbus method call, so resourced doest not know
when window stack is updated. On the other hand, app life cycle update
can be caught by call back function. That is, resourced can catch
timing of window stack update using app life cycle

Change-Id: I626d338e7e45814449a899f2ed9ebf059e9a964a
Signed-off-by: Unsung Lee <unsung.lee@samsung.com>