Signal-Android/app/src/main/res/layout/full_screen_dialog_fragment.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical">

    <androidx.appcompat.widget.Toolbar
        android:id="@+id/full_screen_dialog_toolbar"
        android:layout_width="match_parent"
        android:layout_height="@dimen/signal_m3_toolbar_height"
        android:minHeight="@dimen/signal_m3_toolbar_height"
        app:navigationIcon="@drawable/ic_arrow_left_24"
        app:titleTextAppearance="@style/Signal.Text.TitleLarge"
        tools:title="Dialog Title" />

    <FrameLayout
        android:id="@+id/full_screen_dialog_content"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1" />
</LinearLayout>