Update text of preenforcement storage banner

What does this MR do and why?

It updates the copy of the storage pre-enforcement banner based on #371853+.

Screenshots or screen recordings

before	after

How to set up and validate locally

1. Temporarily apply the patch below
2. Visit a group you are admin in
3. Notice the banner appear on the top of the page
4. Once you're done you can discard the applied patch git checkout -- ee/lib/ee/gitlab/namespaces/storage/enforcement.rb

the patch

diff --git a/ee/lib/ee/gitlab/namespaces/storage/enforcement.rb b/ee/lib/ee/gitlab/namespaces/storage/enforcement.rb
index 19f54fffea3..7bac5dd1737 100644
--- a/ee/lib/ee/gitlab/namespaces/storage/enforcement.rb
+++ b/ee/lib/ee/gitlab/namespaces/storage/enforcement.rb
@@ -20,6 +20,7 @@ def self.enforce_limit?(namespace)
           end
 
           def self.show_pre_enforcement_banner?(namespace)
+            return true
             root_namespace = namespace.root_ancestor
 
             return false unless ::Gitlab::CurrentSettings.should_check_namespace_plan?

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #371853