adapter_camera_item.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/camera"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#f7fafc">

    <ImageView
        android:layout_width="36dp"
        android:layout_height="36dp"
        android:layout_centerInParent="true"
        android:src="@drawable/picture_camera"/>

</RelativeLayout>