Messaging: define app category

Change-Id: I045f394cd2dfa9018cb5d9463c35371bc8814690
Signed-off-by: Joey <joey@lineageos.org>

AndroidManifest.xml

@@ -59,6 +59,7 @@
     <application
         android:name="com.android.messaging.BugleApplication"
         android:allowBackup="false"
+        android:appCategory="social"
         android:icon="@drawable/ic_launcher"
         android:label="@string/app_name"
         android:theme="@style/BugleTheme"