Made folder selection scrollbar visible

app/src/main/res/drawable/scroll_thumb_dialog.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+    <item>
+        <shape android:shape="rectangle">
+            <solid android:color="@color/greyAccent" />
+            <size android:width="9dp" android:height="60dp" />
+        </shape>
+    </item>
+</selector>

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

@@ -44,6 +44,7 @@
         android:layout_height="wrap_content"
         android:layout_marginTop="6dp"
         android:scrollbarStyle="outsideOverlay"
+        android:scrollbarThumbVertical="@drawable/scroll_thumb_dialog"
         android:scrollbars="vertical"
         app:layout_constrainedHeight="true"
         app:layout_constraintBottom_toBottomOf="parent"