Default apps setting for managed profile

1. Print settings already support managed profile. Follow the UI of that.
ProfileSettingsPreferenceFragment is created to act as the base class
for per-profile setting.

2. Only show browser and dialer default setting in managed profile.

BUG=26707733

Change-Id: I20d00203e14db58ec03638f692dd83a1bd50c59c

src/com/android/settings/applications/ManageAssist.java

@@ -18,9 +18,11 @@ package com.android.settings.applications;
 
 import android.app.AlertDialog;
 import android.content.ComponentName;
+import android.content.Context;
 import android.content.DialogInterface;
 import android.os.Bundle;
 import android.os.Handler;
+import android.os.UserManager;
 import android.provider.Settings;
 import android.support.v14.preference.SwitchPreference;
 import android.support.v7.preference.Preference;
@@ -28,6 +30,7 @@ import android.support.v7.preference.Preference;
 import com.android.internal.logging.MetricsLogger;
 import com.android.settings.R;
 import com.android.settings.SettingsPreferenceFragment;
+import com.android.settings.Utils;
 import com.android.settings.voice.VoiceInputListPreference;
 
 /**
@@ -175,4 +178,8 @@ public class ManageAssist extends SettingsPreferenceFragment
         mDefaultAssitPref.setValue(assistPackage);
         updateUi();
     }
+
+    public static boolean isAvailable(Context context) {
+        return !Utils.isManagedProfile(UserManager.get(context));
+    }
 }