Remove style that breaks pre-L builds and isn't necessary anyway

chrome/android/java/res/layout/autofill_card_unmask_prompt.xml

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Copyright 2014 The Chromium Authors. All rights reserved.
 
      Use of this source code is governed by a BSD-style license that can be
      found in the LICENSE file.
 -->
 
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content">
@@ skipping 158 matching lines @@
         android:layout_alignStart="@+id/controls_container"
         android:layout_alignEnd="@+id/controls_container"
         android:orientation="horizontal"
         android:gravity="center"
         android:visibility="gone">
 
         <ProgressBar
             android:id="@+id/verification_progress_bar"
             android:layout_width="16dp"
             android:layout_height="16dp"
-            style="@android:style/Widget.Material.Light.ProgressBar.Small"
             android:visibility="gone" />
 
         <!--  TODO(estade): add a real content description for this image. -->
         <ImageView
             android:id="@+id/verification_success"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:src="@drawable/verify_checkmark"
             android:visibility="gone"
             android:contentDescription="@null" />
 
         <TextView
             android:id="@+id/verification_message"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_marginStart="8dp"
             android:textColor="?attr/colorAccent"
             android:textSize="12sp" />
     </LinearLayout>
 </RelativeLayout>