CLOUDSTACK-7903: Decreased minimal usage aggregation range value

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>
(cherry picked from commit 9b907902d2d424bc8b3136d97196457f42738fff)
Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>

Conflicts:
	server/src/com/cloud/network/router/VirtualNetworkApplianceManagerImpl.java
	usage/src/com/cloud/usage/UsageManagerImpl.java