Use proper value for osap_share_extension

Fixes the following warning when running tempest:

  osapi_share_extension is set to deprecated path:
    manila.api.openstack.share.contrib.standard_extensions
  Please set your flag or manila.conf settings for osapi_share_extension to:
    manila.api.contrib.standard_extensions

Change-Id: Ida45c3fc6c429d7705b64ec7f09603c839889ab2
Merge "Use proper value for osap_share_extension"