[FIX] cf: fix background color of conditional formatting preview

The color of the background of the conditional formatting preview
was not correct because of a wrongly placed `bg-white`.

closes #7491

Task: 5343875
Signed-off-by: Lucas Lefèvre (lul) <lul@odoo.com>

Author: hokolomopo

src/components/side_panel/conditional_formatting/cf_preview/cf_preview.xml

@@ -24,7 +24,7 @@
         <t t-else="">
           <div
             t-att-style="getPreviewImageStyle(cf.rule)"
-            class="o-cf-preview-icon d-flex justify-content-around align-items-center me-2 bg-white border">
+            class="o-cf-preview-icon d-flex justify-content-around align-items-center me-2 border">
             123
           </div>
         </t>

tests/conditional_formatting/__snapshots__/conditional_formatting_panel_component.test.ts.snap

@@ -54,7 +54,7 @@ exports[`UI of conditional formats Conditional format list simple snapshot 1`] =
             </div>
             
             <div
-              class="o-cf-preview-icon d-flex justify-content-around align-items-center me-2 bg-white border"
+              class="o-cf-preview-icon d-flex justify-content-around align-items-center me-2 border"
               style="background:#FF0000; "
             >
                123 
@@ -141,7 +141,7 @@ exports[`UI of conditional formats Conditional format list simple snapshot 1`] =
             </div>
             
             <div
-              class="o-cf-preview-icon d-flex justify-content-around align-items-center me-2 bg-white border"
+              class="o-cf-preview-icon d-flex justify-content-around align-items-center me-2 border"
               style="background-image: linear-gradient(to right, #FF00FF, #123456)"
             >
                123