Center the file status icon

At the moment it is aligned to the beginning of the `Status` column. It
looks more visually consistent when it is placed in the middle of it.

Change-Id: Id028f4e1d026776fb340969b173c35ecdb22bbc9

owners/web/gr-files.ts

diff --git a/owners/web/gr-files.ts b/owners/web/gr-files.ts
index 1f0c7ef..26ee727 100644
--- a/owners/web/gr-files.ts
+++ b/owners/web/gr-files.ts
@@ -214,6 +214,7 @@
         }
         gr-icon {
           padding: var(--spacing-xs) 0px;
+          margin-left: 9px;
         }
         :host([file-status='missing']) gr-icon.status {
           color: #ffa62f;