Signal-Android/app/src/main/res/layout/fragment_media_preview_v2.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout 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:background="@color/signal_dark_colorSurface">

    <androidx.viewpager2.widget.ViewPager2
        android:id="@+id/media_pager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:clickable="true"
        android:focusable="true"
        android:layoutDirection="ltr" />

    <LinearLayout
        android:id="@+id/media_preview_details_container"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        android:alpha="0"
        android:animateLayoutChanges="false"
        android:background="@color/signal_dark_colorSurface_87"
        android:gravity="bottom"
        android:orientation="vertical"
        android:visibility="invisible"
        tools:visibility="visible">

        <org.thoughtcrime.securesms.mediapreview.caption.ExpandingCaptionView
            android:id="@+id/media_preview_caption"
            style="@style/Signal.Text.Body"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="bottom"
            android:paddingStart="16dp"
            android:paddingTop="16dp"
            android:paddingEnd="16dp"
            android:paddingBottom="8dp"
            android:textColor="@color/core_white"
            tools:text="With great power comes great responsibility." />

        <org.thoughtcrime.securesms.mediapreview.MediaPreviewPlayerControlView
            android:id="@+id/media_preview_playback_controls"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:animateLayoutChanges="true"
            android:background="@color/transparent"
            android:paddingTop="8dp" />

    </LinearLayout>

    <com.google.android.material.appbar.AppBarLayout
        android:id="@+id/toolbar_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/signal_dark_colorSurface_87"
        app:elevation="0dp">

        <View
            android:id="@+id/toolbar_cutout_spacer"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:visibility="gone" />

        <com.google.android.material.appbar.MaterialToolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="@dimen/signal_m3_toolbar_height"
            android:background="@android:color/transparent"
            android:minHeight="@dimen/signal_m3_toolbar_height"
            android:theme="?actionBarStyle"
            app:navigationIcon="@drawable/ic_arrow_left_white_24" />

    </com.google.android.material.appbar.AppBarLayout>

</androidx.coordinatorlayout.widget.CoordinatorLayout>