Fix bug where app name is wrong in all languages except English.

The "app_name" string needs to be defined in an Android resources XML file
instead of in android_chrome_strings.grd so the string isn't copied into
every language (which makes it impossible to override the string from a
single strings.xml file)

BUG=441424

Review URL: https://codereview.chromium.org/800953002

Cr-Commit-Position: refs/heads/master@{#308189}

chrome/android/java/res/values/app_name.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. -->
+
+<resources xmlns:android="http://schemas.android.com/apk/res/android">
+    <!-- The application name.
+
+         The value of this string may be overridden in an APK by including a
+         string with the same name but a different value (e.g. "Chrome Shell").
+
+         Note: this must live in app_name.xml rather than
+         android_chrome_strings.grd so the string isn't copied into every
+         language (which makes it impossible to override the string from a
+         single strings.xml file). -->
+    <string name="app_name">Chromium</string>
+</resources>

chrome/android/java/strings/android_chrome_strings.grd

@@ -93,10 +93,6 @@
   </translations>
   <release allow_pseudo="false" seq="1">
     <messages fallback_to_english="true">
-      <message name="IDS_APP_NAME" desc="The application name" translateable="false">
-        Chromium
-      </message>
-
       <!-- Generic strings -->
       <message name="IDS_OK" desc="Label for a confirm button. Used in multiple contexts. [CHAR-LIMIT=20]">
         OK

chrome/android/shell/java/AndroidManifest.xml.jinja2

@@ -38,7 +38,7 @@
 
     <application android:name="org.chromium.chrome.shell.ChromeShellApplication"
             android:icon="@mipmap/app_icon"
-            android:label="Chrome Shell">
+            android:label="@string/app_name">
         <activity android:name="org.chromium.chrome.shell.ChromeShellActivity"
                   android:launchMode="singleTask"
                   android:theme="@style/MainTheme"

chrome/android/shell/res/values/strings.xml

@@ -7,6 +7,7 @@
  -->
 
 <resources>
+    <string name="app_name">Chrome Shell</string>
     <string name="url_hint">Type URL Here</string>
     <string name="print_menu">Print…</string>
     <string name="signin_select_account">Select Account</string>