Problems displaying a button in android

That's because ListViewyou are assigning the value wrap_contentto the property android:layout_height, which is what defines the height that the ListView will have. Being wrap_content, the ListView will be as large as the number of elements it has. If your ListView has 20 items, the list will scroll off the screen and you will have to scroll to see the full list. And if you have any items below the ListView, that will also roll off the screen.

To fix your problem, give the ListView a fixed (static) size. Like for example, a height of 400dp: android:layout_height="400dp". Try different values ​​until the ListView is a size that allows room to color the button below it without it going off screen.

edited

Another possible solution is the following. Place the ListViewabove of the button with the property: android:layout_above="@id/coberturas_list". That way you can use wrap_contentin the ListView and not have to worry about screen sizes.

<ListView
    android:id="@+id/coberturas_list"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_below="@+id/textAseguradora"
    android:drawSelectorOnTop="true"
    android:divider="@null"
    tools:listitem="@layout/list_item_detalle_cobertura" />

<Button
    android:text="Continuar"
    android:layout_width="match_parent"
    android:layout_height="30dp"
    android:background="@color/radio_button_azul"
    android:gravity="center"
    android:layout_above="@+id/coberturas_list" <!--Coloca el listView arriba del boton-->
    android:layout_gravity="center"
    android:textColor="@color/colorWhite"
    android:id="@+id/btnContinuar" />

You already have an answer marked as valid but I'll pass you my layout code. With this code you don't have to give a fixed size to the listview.

The listview is displayed in full screen with a button at the bottom of the listview, try it out and see if you like it.

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="6dip"
android:orientation="vertical"
tools:context="net.pablo.android.app.LVActivity">

<ListView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/listview"
    android:layout_below="@+id/inputSearch"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_weight="1"/>

<Button
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_below="@+id/listview"
    android:text="Mostrar mapa"
    android:id="@+id/btn_mapaCompleto"
    android:layout_weight="0"/>

</LinearLayout>

The interface design has some problems:

1. It's not a good idea to enclose a listView inside a ScrollView as it can cause scrolling issues, use a NestedScrollView instead.
2. The RelativeLayout inside the LinearLayout is unnecessary, since the only relationships you take into account are the vertical ones.

Here is a simplified version of the code, although different, which I think can be adjusted to your needs.

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/linearPadre"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_marginLeft="10dp"
    android:layout_marginRight="10dp"
    android:background="@drawable/tema_fondo"
    android:orientation="vertical">

    <ImageView
        android:id="@+id/image1"
        android:layout_width="match_parent"
        android:layout_height="65dp"
        android:layout_alignParentTop="true"
        android:src="@drawable/tema_icono_paso_3" />


    <ImageView
        android:id="@+id/idHeaderCobertura"
        android:layout_width="match_parent"
        android:layout_height="80dp"
        android:layout_below="@+id/image1"
        android:src="@drawable/cobertura" />

    <TextView
        android:id="@+id/textAseguradora"
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:layout_below="@+id/idHeaderCobertura"
        android:layout_gravity="center"
        android:ems="18"
        android:gravity="center_vertical"
        android:text="Aseguradora"
        android:textAlignment="center"
        android:textColor="@color/colorGreen" />


    <ListView
        android:id="@+id/coberturas_list"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/textAseguradora"
        android:layout_above="@+id/btnContinuar"
        android:drawSelectorOnTop="true"
        android:divider="@null"
        tools:listitem="@layout/list_item_detalle_cobertura" />


    <Button
        android:id="@+id/btnContinuar"
        android:layout_width="match_parent"
        android:layout_height="30dp"
        android:layout_alignParentBottom="true"
        android:layout_gravity="center"
        android:background="@color/radio_button_azul"
        android:gravity="center"
        android:text="Continuar"
        android:textColor="@color/colorWhite" />

</RelativeLayout>

I hope it helps.