Add upload policy for glance v2 api

Related to bug 1250918

There currently exists no check in set_data function for glance
api v2 in the policy layer. This patch adds upload_image policy.

DocImpact

Change-Id: Ibccc78f8bccff3baa5aca574cf17bd14c5403ca2
Merge "Add upload policy for glance v2 api"