Support vnf_release_date_time in manifest

SOL004 v2.6.1 changes the manifest metadata key name from
'vnf_release_data_time' in v2.4.1 to 'vnf_release_date_time'. Support
the new chagnes while keeping backward compatibile with v2.4.1.

Change-Id: I205285f05963dc4d60d6867866b5b2fe114d8da3
Issue-ID: VNFSDK-420
Signed-off-by: Lianhao Lu <lianhao.lu@intel.com>
3 files changed