fix overlay background color in dark mode

src-ui/src/app/components/dashboard/widgets/upload-file-widget/upload-file-widget.component.scss

@@ -34,6 +34,6 @@ form {
   pointer-events: none;
 }
 
-.ngx-file-drop__drop-zone--over {
+::ng-deep .ngx-file-drop__drop-zone--over {
   background-color: var(--ngx-primary-faded) !important;
-}
+}

src-ui/src/theme.scss

@@ -247,6 +247,10 @@ table.table {
 .main-dropzone {
   height: 100%;
   width: 100%;
+
+  &.ngx-file-drop__drop-zone--over {
+    background-color: transparent !important;
+  }
 }
 
 .global-dropzone-overlay {