Updates to snapshots in CNV

Updated snapshot indications documentation to better
indicate the meaning of each indication.
Added a new indication that was added in 4.19.

Signed-off-by: Shelly Kagan <skagan@redhat.com>

Author: ShellyKa13

modules/virt-verifying-online-snapshot-creation-with-snapshot-indications.adoc

@@ -20,5 +20,6 @@ Snapshot indications are contextual information about online virtual machine (VM
 
 . Verify the status of your online VM snapshot by viewing the values of the `status.indications` parameter:
 * `Online` indicates that the VM was running during online snapshot creation.
-* `GuestAgent` indicates that the QEMU guest agent was running during online snapshot creation.
-* `NoGuestAgent` indicates that the QEMU guest agent was not running during online snapshot creation. The QEMU guest agent could not be used to freeze and thaw the file system, either because the QEMU guest agent was not installed or running or due to another error.
+* `GuestAgent` indicates that the QEMU guest agent was active and successfully quiesced the guest file system for the online snapshot. This results in an application-consistent snapshot, preserving data integrity as if the applications had been gracefully shut down.
+* `NoGuestAgent` indicates that the QEMU guest agent was not installed, or not ready to quiesce the file system during the online snapshot. This results in a crash-consistent snapshot, which captures the VM's state like an abrupt power-off. As a result, application consistency is not guaranteed, which causes a risk of data issues for critical applications. For higher reliability, install and run the guest agent, or retry the snapshot.
+* `QuiesceFailed` indicates that an attempt to quiesce the file system failed during the online snapshot process. This means that the snapshot was created, but it is not necessarily application-consistent. To achieve proper consistency, retry the snapshot.