multiline_dialog.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <EditText
        android:id="@+id/multiline_edit_text"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:lines="8"
        android:minLines="6"
        android:maxLines="10" />

</LinearLayout>