Layout issues when using dynamic height

[davidmigloz]

When using dynamic height the first row takes the full available height.

Example:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http:https://schemas.android.com/apk/res/android"
    xmlns:keyboard="http:https://schemas.android.com/apk/res-auto"
    xmlns:tools="http:https://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="50dp"
    tools:context="com.davidmiguel.sample.MainActivity">

    <TextView
        android:id="@+id/amount"
        style="@style/Base.TextAppearance.AppCompat.Title"
        android:layout_width="wrap_content"
        android:layout_height="50dp"
        android:layout_gravity="center"
        android:layout_margin="20dp"
        android:gravity="center"
        android:text="0"
        android:textSize="40sp"/>

    <com.davidmiguel.numberkeyboard.NumberKeyboard
        android:id="@+id/numberKeyboard"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        keyboard:keyboardType="integer"/>

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="Hello!!"/>

</LinearLayout>