Avoid to skip app window due to un-assigned sending to bottom state while app window sort

should assign value of WindowToken.sendingToBottom according to the state of this token is moved to top or bottom
to avoid app window is skiped incorrectly due to sending to bottom state is un-assigned while app window sort
and finding focus window.

Change-Id: I190838d1d01ca229155d5176930178ab41335556
Signed-off-by: tingna_sung <tingna_sung@htc.com>
Doesn't re-sort app windows when move task to top

To avoid app window isn't moved by new task order when move task to top

Change-Id: I5f8a901bb2f20a163b7fa0a59d1dc58c1fca5f1f
Signed-off-by: tingna_sung <tingna_sung@htc.com>