Fix possible memory corruptions in policy decision dispatching logic

Fix possible memory corruptions in policy decision dispatching logic

In some cases suspended policy decisions could be deleted by new policy
decision events. This patch fixes that also providing some feedback for
policy decisions that can't be suspended at all.
This patch is a port of this patch:
http://165.213.202.130:8080/#/c/70024/
by Kamil Klimek

Bug: http://107.108.218.239/bugzilla/show_bug.cgi?id=10629
Reviewed by: Piotr Tworek, arno renevier

Change-Id: I4431c4c8e9ec0deb4f7c76ea494ef47bec6de0d5
Signed-off-by: Tomasz Czekala <t.czekala@partner.samsung.com>