ASACORE-1034 Suppress periodic maintenance timer when it is not needed

With this change, this 1-second timer will be turned off
when there's no active advertisement or outgoing message
queued.

Change-Id: Ib57c5de9be8c3db6d17bc8231ab7948de181fde4
Signed-off-by: Way Vadhanasin <wayvad@microsoft.com>
Merge "ASACORE-1034 Suppress periodic maintenance timer when it is not needed"