Fix policy.py

Because inside check_policy() there is hardcoded
'share' target prepended to all policies, any
policy we check will be checked against 'share'
policy. Change check_policy() to use explicit
target and action instead of just action.
Change wrap_check_policy decorator to be a
decorator maker which accepts resource name
as an argument.
Closes-Bug: #1274951
Partial-Bug: #1271943

Change-Id: I85c184035619d78107d56ea94918f608d8d7c282
Merge "Fix policy.py"