Add voicemail tab if there are active providers.

Bug: 21328994
Change-Id: Id6cd45c5614fafcc6f01842a8ec1eaba45dc0928
diff --git a/res/drawable/tab_voicemail.xml b/res/drawable/tab_voicemail.xml
new file mode 100644
index 0000000..568891b
--- /dev/null
+++ b/res/drawable/tab_voicemail.xml
@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright (C) 2015 The Android Open Source Project
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~      http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License
+  -->
+
+<ripple xmlns:android="http://schemas.android.com/apk/res/android"
+    android:color="@color/tab_ripple_color">
+
+    <item>
+        <bitmap android:src="@drawable/ic_voicemail_24dp"
+            android:gravity="center" />
+    </item>
+
+    <item android:id="@android:id/mask">
+        <color android:color="@android:color/white" />
+    </item>
+
+</ripple>
diff --git a/res/values/strings.xml b/res/values/strings.xml
index e3b2682..21cd890 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -471,12 +471,19 @@
          [CHAR LIMIT=30] -->
     <string name="call_log_voicemail_title">Voicemail</string>
 
+    <!-- Accessibility text for the tab showing recent and favorite contacts who can be called.
+         [CHAR LIMIT=40] -->
     <string name="tab_speed_dial">Speed dial</string>
 
+    <!-- Accessibility text for the tab showing the call log of recent calls. [CHAR LIMIT=40] -->
     <string name="tab_recents">Recents</string>
 
+    <!-- Accessibility text for the tab showing the user's contacts. [CHAR LIMIT=40] -->
     <string name="tab_all_contacts">Contacts</string>
 
+    <!-- Accessibility text for the tab showing the user's voicemails. [CHAR LIMIT=40] -->
+    <string name="tab_voicemail">Voicemail</string>
+
     <!--  Text displayed when user swipes out a favorite contact -->
     <string name="favorite_hidden">Removed from favorites</string>
     <!--  Text displayed for the undo button to undo removing a favorite contact -->