cros: Update saml banner text and style.

chrome/app/chromeos_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <!-- ChromeOS-specific strings (included from generated_resources.grd).
      Everything in this file is wrapped in <if expr="pp_ifdef('chromeos')">. -->
 <grit-part>
   <message name="IDS_EMPTY_STRING" desc="Empty string, exist only to make code generic. No translation required.">
   </message>
   <!-- Idle logout dialog for retail mode -->
   <message name="IDS_IDLE_LOGOUT_TITLE" desc="Dialog title for the idle logout dialog. Used in retail mode only.">
     Are you still there?
   </message>
@@ skipping 406 matching lines @@
     Only retrieve synced settings and data
   </message>
   <message name="IDS_LOGIN_PASSWORD_CHANGED_MIGRATE" desc="Migrate option of the password changed dialog">
     Migrate all Chrome OS data to the new password
 (requires previous password)
   </message>
   <message name="IDS_LOGIN_PREVIOUS_PASSWORD" desc="Password field text on the password changed dialog">
     Previous password
   </message>
   <message name="IDS_LOGIN_SAML_NOTICE" desc="Text message displayed above SAML portal to learly indicate that the user is being redirected to another sign-in provider.">
-    You are being redirected below to a sign-in service hosted by <ph name="SAML_DOMAIN">$1<ex>saml.com</ex></ph>.
+    The sign-in service below is hosted by <ph name="SAML_DOMAIN">$1<ex>saml.com</ex></ph>. Sign in to continue.
   </message>
   <message name="IDS_LOGIN_CONFIRM_PASSWORD_TITLE" desc="Title for the confirm password dialog.">
     Please confirm your password.
   </message>
   <message name="IDS_LOGIN_CONFIRM_PASSWORD_HINT" desc="Hint for the password field on the confirm password dialog.">
     Type your password here to confirm.
   </message>
   <message name="IDS_LOGIN_CONFIRM_PASSWORD_CONFIRM_BUTTON" desc="Label for the confirm button on the confirm password dialog.">
     Confirm
   </message>
@@ skipping 3589 matching lines @@
   <message name="IDS_CHARGER_REPLACEMENT_DIALOG_TITLE" desc="Title of the charger replacement UI dialg">
     Check charger
   </message>
   <message name="IDS_FLAGS_ENABLE_SYSTEM_SOUNDS_NAME" desc="Name of the flag to enable system sounds independently from ChromeVox.">
     Enable system sounds
   </message>
   <message name="IDS_FLAGS_ENABLE_SYSTEM_SOUNDS_DESCRIPTION" desc="Description of the flag to enable system sounds independently from ChromeVox.">
     System sounds will be played independently from ChromeVox.
   </message>
 </grit-part>