Quelle  notice_with_close_button.xml

<?xml version="1.0" encoding="utf-8"?>
<com.google.android.material.card.MaterialCardView 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:id="@+id/notice_layout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginLeft="8dp"
    android:layout_marginTop="@dimen/notice_views_vertical_margin"
    android:layout_marginRight="8dp"
    android:layout_marginBottom="@dimen/notice_views_vertical_margin"
    android:clickable="false"
    android:outlineProvider="none"
    android:visibility="gone"
    app:cardBackgroundColor="?attr/colorPrimary"
    app:cardCornerRadius="@dimen/cardview_border_radius"
    app:cardElevation="@dimen/notice_views_elevation"
    app:strokeWidth="0dp"
    tools:visibility="visible">

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

        <TextView
            android:id="@+id/notice_text"
            style="@style/Threema.TextAppearance.BodyLarge"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginLeft="16dp"
            android:layout_marginTop="12dp"
            android:layout_marginBottom="12dp"
            android:clickable="false"
            android:gravity="left"
            android:hyphenationFrequency="full"
            android:textColor="?attr/colorOnPrimary"
            android:textSize="16sp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toLeftOf="@+id/close_button"
            app:layout_constraintTop_toTopOf="parent"
            tools:text="@tools:sample/lorem" />

        <com.google.android.material.button.MaterialButton
            android:id="@+id/close_button"
            style="@style/Threema.MaterialButton.Minimal"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="0dp"
            android:contentDescription="@string/close"
            app:icon="@drawable/ic_close"
            app:iconTint="?attr/colorOnPrimary"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

    </androidx.constraintlayout.widget.ConstraintLayout>

</com.google.android.material.card.MaterialCardView>