[ProfilePicker] Color picker border in dark mode

Updates the color picker border color to Google grey 700.

Bug: 1108289
Change-Id: I596bfa0c914c57fb6807d0e0b76bf8cbbb7a541a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2409435
Auto-Submit: Alex Ilin <alexilin@chromium.org>
Reviewed-by: Monica Basta <msalama@chromium.org>
Commit-Queue: Monica Basta <msalama@chromium.org>
Cr-Commit-Position: refs/heads/master@{#806612}

chrome/browser/resources/signin/profile_picker/profile_creation_flow/local_profile_customization.html

@@ -106,6 +106,10 @@
     #nameInput {
       --cr-input-placeholder-color: rgba(var(--google-grey-200-rgb), .5);
     }
+
+    #colorPickerContainer {
+      border-color: var(--google-grey-refresh-700);
+    }
   }
 </style>