This patch mentions the following details about the glance cinder
store:
Single store:
Importance of setting the service credentials with the cinder store
configuration options.
Multi store:
1. Mention warning that during store initialization, we require the
credentials in configuration file to validate volume types.
2. Upgrade scenario where the values of configuration parameters
should remain same in single and multi store before and after the
upgrade.
3. Upgrade scenario when single store doesn't contain credentials
in glance config file and we need to transfer Image-Volumes to
service project.
Change-Id: Iff1320f8a4cf0c614f1a71556957a11ccd010147
81772be899