Fix grammatical error in LayoutAnimationController documentation.

import java.util.Random;

/**

 * A layout animation controller is used to animated a layout's, or a view

 * group's, children. Each child uses the same animation but for every one of

 * A layout animation controller is used to animate the children of a layout or a view

 * group. Each child uses the same animation but for every one of

 * them, the animation starts at a different time. A layout animation controller

 * is used by {@link android.view.ViewGroup} to compute the delay by which each

 * child's animation start must be offset. The delay is computed by using