[ExploreSites]: Add new hairline background for last tile of MostLikely

Bug: 970344
Change-Id: I45371307ac8f985b2f09fcfb6bb9e14ce9f2f4bc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1643731Reviewed-by: Theresa <twellington@chromium.org>
Commit-Queue: Cathy Li <chili@chromium.org>
Cr-Commit-Position: refs/heads/master@{#666067}

chrome/android/java/res/drawable/tile_view_hairline_border_background.xml

+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2019 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. -->
+
+<shape
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:shape="oval">
+    <solid android:color="@color/modern_primary_color" />
+    <stroke android:width="1dp" android:color="@color/hairline_stroke_color"/>
+</shape>

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

@@ -7,7 +7,6 @@
 <org.chromium.chrome.browser.suggestions.tile.TopSitesTileView
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
-    xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="@dimen/tile_view_width"
     android:layout_height="wrap_content"
     android:paddingStart="@dimen/tile_view_padding"
@@ -20,7 +19,7 @@
         android:layout_height="@dimen/tile_view_icon_size"
         android:layout_gravity="center_horizontal"
         android:layout_marginTop="@dimen/tile_view_icon_background_margin_top_modern"
-        android:background="@drawable/tile_view_icon_background_modern" />
+        android:background="@drawable/tile_view_hairline_border_background" />
 
     <!-- The main icon. -->
     <ImageView

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

@@ -7,7 +7,6 @@
 <org.chromium.chrome.browser.suggestions.tile.TopSitesTileView
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
-    xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="@dimen/tile_view_width_condensed"
     android:layout_height="wrap_content"
     android:paddingStart="@dimen/tile_view_padding"
@@ -20,7 +19,7 @@
         android:layout_height="@dimen/tile_view_icon_size"
         android:layout_gravity="center_horizontal"
         android:layout_marginTop="@dimen/tile_view_icon_background_margin_top_modern"
-        android:background="@drawable/tile_view_icon_background_modern" />
+        android:background="@drawable/tile_view_hairline_border_background" />
 
     <!-- The main icon. -->
     <ImageView