Почему кнопка не прижимается к низу контейнера?
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<LinearLayout
android:id="@+id/container1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<LinearLayout
android:id="@+id/container2"
android:layout_width="wrap_content"
android:layout_height="60dp"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:orientation="horizontal">
<Button
android:id="@+id/button18"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Button" />
</LinearLayout>
</LinearLayout>
</RelativeLayout>
