Fix tab width in landscape views

On landscape view, the tab text is not on the middle of the tab.
Add tabMaxWidth to make the text centered.

Bug: 1013521
Change-Id: Ic5d1b173f368c1cf3910f86c718c77aaf618bd19
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1856848Reviewed-by: Theresa  <twellington@chromium.org>
Commit-Queue: Lijin Shen <lazzzis@google.com>
Cr-Commit-Position: refs/heads/master@{#705734}

chrome/android/java/res/values/styles.xml

@@ -642,6 +642,7 @@
         <item name="tabPaddingEnd">5dp</item>
         <item name="tabMode">fixed</item>
         <item name="tabGravity">fill</item>
+        <item name="tabMaxWidth">0dp</item>
         <item name="tabTextColor">@color/default_text_color_secondary</item>
         <item name="tabSelectedTextColor">@color/tab_layout_selected_tab_color</item>
         <item name="android:background">@color/modern_primary_color</item>

chrome/android/java/res_download/layout/download_home_tabs.xml

@@ -5,7 +5,6 @@
 -->
 
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:app="http://schemas.android.com/apk/res-auto"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:orientation="vertical">