cleanup: Update Azure cleanup policy

Azure devices are for kept in portal for 7 days after pipeline is run.
This was done to enable developers to rerun the CI jobs. But This seems
to be creating a huge number of devices in Azure portal. To limit this:

- Delete devices if pipeline was successful.
- Delete devices if pipeline was finished more than a day ago.

Signed-off-by: Saheer Babu <saheer.babu@arm.com>