If editing the template file didn’t change the text, it’s likely being generated by BuddyPress core or a filter, not that specific template.
I’d recommend checking for a hook such as bp_core_avatar_admin or overriding the string with a translation plugin like Loco Translate. That approach is usually update-safe and avoids editing plugin core files. If you’re using a custom theme, also make sure it isn’t overriding the BuddyPress template.
