Adding metadata checking to image location proxy layer

Enable image locaton proxy checking metadata when the location changing.
Implemented bp: location-proxy-metadata-checking

Change-Id: If411a454cd2c3e277ea9840cc3d83ec5125bb372
Signed-off-by: Zhi Yan Liu <zhiyanl@cn.ibm.com>
Merge "Adding metadata checking to image location proxy layer"