The ceph-mon and ceph-osd charms changed the default source config
option to be bobcat in the master branches. This breaks focal tests
as the focal-bobcat cloud archive is not a valid source repository.
Update the config options for the test bundles to be explicit in the
source of package updates.
Fix key errors for rbd-pool-name and ec-rbd-metadata-pool
The existing code assumes event.params['rbd-pool-name'] and
event.params['ec-rbd-metadata-pool'] have a key. Set an empty string by
default to be filled by other part of the code.
Follow-up of Iec275190854edcc85915d93db233f444c92fbb17
"iscsi" is the name of the metadata pool by default in the charm and not
to be used for tenant data. The charm can fill out the data pool name
automatically with `def data_pool_name` or can accept a user specified
value. After fixing the issue, the "iscsi" pool will be used only for
hosting gateway.conf as a rados object so reflect the purpose into the
application name for the pool too.
Also, update the command syntax not to print the deprecation warning:
"rbd: --user is deprecated, use --id"
