gecko/mobile/android/base/resources/xml/preferences_devtools.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- This Source Code Form is subject to the terms of the Mozilla Public
   - License, v. 2.0. If a copy of the MPL was not distributed with this
   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->

<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
                  xmlns:gecko="http://schemas.android.com/apk/res-auto"
                  android:title="@string/pref_category_devtools"
                  android:enabled="false">

       <CheckBoxPreference android:key="devtools.debugger.remote-enabled"
                           android:title="@string/pref_developer_remotedebugging" />

       <org.mozilla.gecko.preferences.AlignRightLinkPreference android:title="@string/pref_developer_remotedebugging_docs"
                                                               url="https://developer.mozilla.org/docs/Tools/Remote_Debugging" />

</PreferenceScreen>