fix layout cart

app/src/main/res/layout/activity_cart.xml

 <?xml version="1.0" encoding="utf-8"?>
 
-<androidx.constraintlayout.widget.ConstraintLayout
+<RelativeLayout
     android:layout_height="match_parent"
      android:layout_width="match_parent"
     xmlns:app="http://schemas.android.com/apk/res-auto"
@@ -11,28 +11,49 @@
         android:id="@+id/cAppBar"
         layout="@layout/app_bar"/>
 
-
     <androidx.recyclerview.widget.RecyclerView
         android:id="@+id/rvCart"
         android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        app:layout_constraintTop_toBottomOf="@id/cAppBar"
+        android:layout_height="match_parent"
+        android:layout_above="@id/btCheckout"
+        android:layout_below="@id/cAppBar"
         android:overScrollMode="never"
-        android:padding="12sp"
         app:layoutManager="androidx.recyclerview.widget.GridLayoutManager"
-        tools:listitem="@layout/item_cart"
-        />
+        tools:listitem="@layout/item_cart" />
+
+
+<!--    <androidx.recyclerview.widget.RecyclerView-->
+<!--        android:id="@+id/rvCart"-->
+<!--        android:layout_width="match_parent"-->
+<!--        android:layout_height="match_parent"-->
+<!--        app:layoutManager="androidx.recyclerview.widget.GridLayoutManager"-->
+<!--        tools:listitem="@layout/item_cart"-->
+<!--        android:layout_above="@+id/btCheckout"-->
+<!--        />-->
+
+<!--    <com.google.android.material.button.MaterialButton-->
+<!--        android:id="@+id/btCheckout"-->
+<!--        android:layout_width="match_parent"-->
+<!--        android:layout_height="wrap_content"-->
+<!--        android:text="@string/title_checkout"-->
+<!--        android:padding="15dp"-->
+<!--        android:textSize="16sp"-->
+<!--        android:layout_margin="10dp"-->
+<!--        android:layout_below="@id/rvCart"-->
+<!--        android:layout_alignParentBottom="true"-->
+<!--        android:layout_alignWithParentIfMissing="true"/>-->
 
     <com.google.android.material.button.MaterialButton
         android:id="@+id/btCheckout"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
+        android:layout_alignParentBottom="true"
+        android:background="@color/colorPrimary"
+        android:gravity="center"
         android:text="@string/title_checkout"
-        android:padding="15dp"
-        android:textSize="16sp"
+        android:textAllCaps="true"
         android:layout_margin="10dp"
-        app:layout_constraintBottom_toBottomOf="parent"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintEnd_toEndOf="parent"/>
+        android:textColor="@android:color/white"
+        android:textStyle="bold" />
 
-</androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file
+</RelativeLayout>
\ No newline at end of file