Fix polymer binding for aria-label on OOBE screens.

Bug: 955194
Change-Id: I9b4bbcc58754f84ebda30cb171c49c638bd261c0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1912300Reviewed-by: Roman Sorokin [CET] <rsorokin@chromium.org>
Commit-Queue: Denis Kuznetsov [CET] <antrim@chromium.org>
Cr-Commit-Position: refs/heads/master@{#714892}

chrome/browser/resources/chromeos/login/marketing_opt_in.html

@@ -10,7 +10,7 @@
     <link rel="stylesheet" href="marketing_opt_in.css">
     <link rel="stylesheet" href="oobe_flex_layout.css">
     <oobe-dialog id="marketingOptInOverviewDialog" role="dialog" has-buttons
-        aria-label="[[i18nDynamic(locale, 'marketingOptInScreenTitle')]]">
+        aria-label$="[[i18nDynamic(locale, 'marketingOptInScreenTitle')]]">
       <hd-iron-icon slot="oobe-icon" icon1x="oobe-32:checkmark"
           icon2x="oobe-32:checkmark">
       </hd-iron-icon>

chrome/browser/resources/chromeos/login/security_token_pin.html

@@ -31,7 +31,7 @@
         <div id="pinKeyboardContainer">
           <pin-keyboard id="pinKeyboard"
               has-error="[[hasError_(parameters, userEdited_)]]"
-              aria-label="[[getAriaLabel_(locale, parameters, errorLabelId_,
+              aria-label$="[[getAriaLabel_(locale, parameters, errorLabelId_,
                                            userEdited_)]]"
               on-pin-change="onPinChange_">
             <div id="errorContainer" problem