activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent" 
        android:layout_height="match_parent"
        tools:context=".MainActivity">
    <Button android:layout_width="match_parent" android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_centerHorizontal="true"
            android:id="@+id/btn_detect"
            android:text="Detect"/>
    <com.camerakit.CameraKitView
            android:layout_above="@id/btn_detect"
            android:layout_width="match_parent"
            android:id="@+id/camera_view"
            android:layout_height="match_parent"
            android:adjustViewBounds="true"
            android:keepScreenOn="true"
            app:camera_flash="auto"
            app:camera_facing="back"
            app:camera_focus="continuous"
            app:camera_permissions="camera">
    </com.camerakit.CameraKitView>
    <com.example.imagelove.GraphicOverlay
            android:id="@+id/graphic_overlay"
            android:layout_width="match_parent" 
            android:layout_height="match_parent"/>
</RelativeLayout>