feat(ui): refine data encryption key tooltip for clarity and conciseness

Author: stephdl

core/ui/public/i18n/en/translation.json

@@ -533,7 +533,7 @@
         "not_backed_up": "Not backed up",
         "search_instances": "Search applications",
         "not_backed_up_instances_selected": "Instances not backed up are currently selected",
-        "data_encryption_key_tooltip": "This key encrypts backup data stored on the destination. It is independent of any remote provider credentials. If left empty, a random key is generated automatically. The key is saved in the cluster backup, store it in a safe place or download the cluster backup regularly.",
+        "data_encryption_key_tooltip": "This encryption key is used to protect data in the backup destination and is saved inside your cluster backup. Store it in a safe place, or remember to download the cluster backup regularly.",
         "run_backup": "Run backup",
         "run_backup_now": "Run backup now",
         "last_backup": "Last backup",