Margin updates for library category header

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

@@ -23,13 +23,12 @@
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toTopOf="@+id/category_title"
         tools:tint="?attr/colorAccent"
-        tools:visibility="visible" />
+        tools:visibility="gone" />
 
     <ImageView
         android:id="@+id/collapse_arrow"
         android:layout_width="14dp"
         android:layout_height="wrap_content"
-        android:layout_marginStart="2dp"
         android:contentDescription="@string/select_all"
         android:src="@drawable/ic_expand_less_24dp"
         android:tint="?android:textColorPrimary"
@@ -52,7 +51,6 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:paddingStart="0dp"
-        android:layout_marginStart="4dp"
         android:paddingEnd="4dp"
         android:paddingTop="4dp"
         android:layout_marginTop="28dp"