Updated text on Private Window banner. (#27816)

components/resources/brave_components_strings.grd

@@ -405,7 +405,7 @@
         <message name="IDS_BRAVE_PRIVATE_NEW_TAB_THIS_IS_A" desc="">This is a</message>
         <message name="IDS_BRAVE_PRIVATE_NEW_TAB_PRIVATE_WINDOW" desc="">Private Window</message>
         <message name="IDS_BRAVE_PRIVATE_NEW_TAB_PRIVATE_WINDOW_DESC" desc="">Brave doesn’t remember what you do in a Private Window. Sites you visit won't show up in your history, and cookies vanish when you’re done. Private Windows don’t make you completely anonymous online, though.</message>
-        <message name="IDS_BRAVE_PRIVATE_NEW_TAB_PRIVATE_WINDOW_DESC1" desc="">Brave never remembers what you do in a Private Window. Sites you visit won't show up in your history. Cookies, form data, and site data vanish when you close the window.</message>
+        <message name="IDS_BRAVE_PRIVATE_NEW_TAB_PRIVATE_WINDOW_DESC1" desc="">Brave never remembers what you do in a Private Window. Sites you visit won't show up in your history. Cookies, form data, and site data vanish once you close all open private windows.</message>
         <message name="IDS_BRAVE_PRIVATE_NEW_TAB_PRIVATE_WINDOW_DESC2" desc="">Note that your activity could still be visible to your internet service provider, passive network observers, or your employer (if you're using a work machine or network). For more privacy, open a private window with Tor.</message>
         <message name="IDS_BRAVE_PRIVATE_NEW_TAB_PRIVATE_WINDOW_BUTTON" desc="">Learn more.</message>
         <message name="IDS_BRAVE_PRIVATE_NEW_TAB_PRIVATE_WINDOW_TOR" desc="">Private Window with Tor connectivity</message>