session-android/res/layout/device_add_fragment.xml

<?xml version="1.0" encoding="utf-8"?>

<FrameLayout android:layout_width="match_parent"
             android:layout_height="match_parent"
             android:layout_weight="1"
             xmlns:android="http://schemas.android.com/apk/res/android"
             xmlns:app="http://schemas.android.com/apk/res-auto">

    <org.thoughtcrime.securesms.components.camera.CameraView
            android:id="@+id/scanner"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:camera="0"/>

    <LinearLayout android:id="@+id/overlay"
                  android:layout_width="match_parent"
                  android:layout_height="match_parent"
                  android:orientation="vertical"
                  android:weightSum="2">

        <org.thoughtcrime.securesms.components.ShapeScrim
            android:layout_weight="1"
            android:layout_width="match_parent"
            android:layout_height="match_parent"/>


        <LinearLayout android:orientation="vertical"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:paddingLeft="16dp"
            android:paddingRight="16dp"
            android:background="?android:windowBackground"
            android:gravity="center">

            <ImageView android:id="@+id/devices"
                       android:src="@drawable/ic_devices_white"
                       android:layout_width="wrap_content"
                       android:layout_height="wrap_content"
                       android:tint="@color/gray27"
                       android:transitionName="devices"
                       android:layout_marginBottom="16dp"/>

            <TextView android:text="@string/device_add_fragment__scan_the_qr_code_displayed_on_the_device_to_link"
                      android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:textColor="?android:textColorSecondary"/>


        </LinearLayout>
    </LinearLayout>

</FrameLayout>