Fixes external #2669. Clarify the documentation of the XML attributes...

<?xml version="1.0" encoding="utf-8"?>

grav<?xml version="1.0" encoding="utf-8"?>

<!-- Copyright (C) 2006 The Android Open Source Project

     Licensed under the Apache License, Version 2.0 (the "License");

    <!-- A coordinate in the Y dimension. -->

    <attr name="y" format="dimension" />

    <!-- Specifies how to place an object, both

         its x and y axis, within a larger containing object. -->

    <!-- Specifies how to place the content of an object, both

         on the x and y axis, within the object itself. -->

    <attr name="gravity">

        <!-- Push object to the top of its container, not changing its size. -->

        <flag name="top" value="0x30" />

    <attr name="entries" format="reference" />

    <!-- Standard gravity constant that a child can supply to its parent.

         Defines how to place an object, both

         its x and y axis, within a larger containing object. -->

         Defines how to place the view, both its x and y axis, within is parent view group. -->

    <attr name="layout_gravity">

        <!-- Push object to the top of its container, not changing its size. -->

        <flag name="top" value="0x30" />