<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/gray4">

<!--First child of CoordinatorLayout layout
should be App Bar Layout-->
<com.google.android.material.appbar.AppBarLayout
android:id="@+id/appBarLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

<!-- Add Material toolbar make the layout_scrollFlags
to scroll|enterAlways (Important)-->

<com.google.android.material.appbar.CollapsingToolbarLayout
android:id="@+id/toolbar_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_scrollFlags="scroll|exitUntilCollapsed">

<FrameLayout
android:id="@+id/message_commented"
android:layout_width="match_parent"
android:background="@color/gray4"
android:layout_height="wrap_content"
android:layout_marginTop="?attr/actionBarSize">

</FrameLayout>

<androidx.appcompat.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@color/white"
app:contentInsetStart="0dp"
app:layout_collapseMode="pin"
app:layout_constraintTop_toTopOf="parent">

<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">

<ImageView
android:id="@+id/ivBack"
android:layout_width="24dp"
android:layout_height="24dp"
android:layout_marginStart="20dp"
android:src="@drawable/ic_arrow_back"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:tint="@color/black" />

<androidx.constraintlayout.widget.ConstraintLayout
android:id="@+id/infoLayout"
android:layout_width="0dp"
android:layout_height="0dp"
android:paddingHorizontal="16dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="@+id/ivBack"
app:layout_constraintTop_toTopOf="parent">

<TextView
android:id="@+id/tvTitle"
style="@style/tv16medium"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginHorizontal="16dp"
android:textAlignment="textStart"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />


</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.appcompat.widget.Toolbar>

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

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

Оберните код в теги: 3 символа ` до и после кода (в случае одиночной конструкции достаточно 1 ` с обеих сторон). Спасибо!