Fixes ceph key import failures

There is an issue with HA deployments where sometimes key imports fail
for Ceph which seem to occur around 50% of the time.  When logging in
after a failure, the key import seems to work which indicates it may be
a race condition.  In addition, sometimes the keyring that is created
is missing the "caps" section of the file, which will also fail import.

This patch adds a retries for a minute to try to import the key.  It
also moves creating/importing to the same Exec because there is
evidence that the file is being modified by some other process right
after the file content is created in the previous exec.

JIRA: APEX-563

Change-Id: Ie8cfeb4803f6bed95f9e612eeb37c5cdf2d76617
Signed-off-by: Tim Rozet <trozet@redhat.com>