MD Settings: compose a <paper-radio-button> instead of wrapping one in <controlled-radio-button>

chrome/browser/resources/settings/appearance_page/home_url_input.html

 <link rel="import" href="chrome://resources/html/assert.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-input/paper-input.html">
 <link rel="import" href="chrome://resources/cr_elements/policy/cr_policy_pref_behavior.html">
 <link rel="import" href="chrome://resources/cr_elements/policy/cr_policy_pref_indicator.html">
 <link rel="import" href="../controls/pref_control_behavior.html">
 <link rel="import" href="appearance_browser_proxy.html">
 
 <dom-module id="home-url-input">
   <template>
     <style>
       :host {
-        -webkit-margin-start: 4px;
         cursor: auto;
         display: inline-block;
       }
+
+      #outerDiv {
+        justify-content: space-between;
+      }
     </style>
     <div id="outerDiv" class="layout horizontal center">
       <paper-input id="input" value="{{value}}" no-label-float
           label="$i18n{enterCustomWebAddress}" error-message="$i18n{notValid}"
           on-change="onChange_" on-keydown="onKeydown_" on-input="validate_"
           invalid="{{invalid}}" tabindex$="[[getTabindex_(canTab)]]"
           disabled="[[isDisabled_(disabled, pref.*)]]"
           stop-keyboard-event-propagation>
       </paper-input>
       <template is="dom-if" if="[[hasPrefPolicyIndicator(pref.*)]]">
         <cr-policy-pref-indicator pref="[[pref]]" icon-aria-label="[[label]]">
         </cr-policy-pref-indicator>
       </template>
     </div>
   </template>
   <script src="home_url_input.js"></script>
 </dom-module>