Fix ADD_VOICEMAIL intent.

Bug: 21082935
Change-Id: I7bd834a9e5327ddce139bd07c7f0a6b0be5fcc86
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 59d0753..7ad2a4e 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -587,6 +587,7 @@
             <intent-filter >
                 <!-- DO NOT RENAME. There are existing apps which use this string. -->
                 <action android:name="com.android.phone.CallFeaturesSetting.ADD_VOICEMAIL" />
+                <category android:name="android.intent.category.DEFAULT" />
             </intent-filter>
         </activity>