Update two chromeos system dialogs to reuse more DialogDelegateView

chrome/app/chromeos_strings.grdp

Index: chrome/app/chromeos_strings.grdp
diff --git a/chrome/app/chromeos_strings.grdp b/chrome/app/chromeos_strings.grdp
index 06e2d4315e2d4cb868d02dc58061fc36f10702db..07eca4b27186fcd8ee6af164fe075409fb4bb7d2 100644
--- a/chrome/app/chromeos_strings.grdp
+++ b/chrome/app/chromeos_strings.grdp
@@ -5592,10 +5592,11 @@ Battery full
     Multiple sign-in
   </message>
   <message name="IDS_MULTIPROFILES_INTRO_MESSAGE" desc="Content of the multi-profiles intro dialog shown when the user adds another user in multi-profiles mode.">
-    This feature allows you to access quickly any signed-in user without requiring a password.
+    This feature allows you to quickly access any signed-in user without requiring a password.
+
+Only use this feature with accounts you trust.
   </message>
   <message name="IDS_MULTIPROFILES_INTRO_EXPLANATION" desc="Content of the multi-profiles intro dialog shown when the user adds another user in multi-profiles mode.">
-    Only use this feature with accounts you trust.
   </message>
   <message name="IDS_MULTIPROFILES_INTRO_NOSHOW_AGAIN" desc="In multi-profiles intro dialog, text for no-show-again option.">
     Got it, don't show me this again.