sys user split: first pass updating Settings

Update various places in Settings to use "admin" ueser flag
instead of checking user id "0".  This should be no-op in
single user mode since the only admin user would be user 0.
In split system user mode, this will correctly ACL admin
user instead of non-interactive system user.

Bug: 19913735
Change-Id: Ida4d59c5f689ea0dc34b3b3ff0822b087fa0afd6

src/com/android/settings/TestingSettings.java

@@ -17,7 +17,7 @@
 package com.android.settings;
 
 import android.os.Bundle;
-import android.os.UserHandle;
+import android.os.UserManager;
 import android.preference.PreferenceActivity;
 import android.preference.PreferenceScreen;
 
@@ -29,7 +29,8 @@ public class TestingSettings extends PreferenceActivity {
         
         addPreferencesFromResource(R.xml.testing_settings);
 
-        if (UserHandle.myUserId() != UserHandle.USER_OWNER) {
+        final UserManager um = UserManager.get(this);
+        if (!um.isAdminUser()) {
             PreferenceScreen preferenceScreen = (PreferenceScreen)
                     findPreference("radio_info_settings");
             getPreferenceScreen().removePreference(preferenceScreen);