Change the title of DocumentsUI from "Files" to "Downloads".

BUG=27683277

Change-Id: I429cae8804b8f318f58039fc63d081c2a864fad0
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 6fe239e..b3e0e07 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -45,7 +45,7 @@
             android:name=".LauncherActivity"
             android:theme="@android:style/Theme.NoDisplay"
             android:icon="@drawable/ic_files_app"
-            android:label="@string/files_label">
+            android:label="@string/downloads_label">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
@@ -56,7 +56,7 @@
             android:name=".FilesActivity"
             android:theme="@style/DocumentsTheme"
             android:icon="@drawable/ic_files_app"
-            android:label="@string/files_label"
+            android:label="@string/downloads_label"
             android:documentLaunchMode="intoExisting">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />