[Android] Change color of sync_off icon in Main settings page

Change color to grey_500 for both light mode and dark mode.

Screenshot: https://crbug.com/1135915#c4

Bug: 1135915
Change-Id: I29e790195a4f6d276dceb32aab1d19ba5dc7744e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2456527Reviewed-by: Boris Sazonov <bsazonov@chromium.org>
Commit-Queue: Tanmoy Mollik <triploblastic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#815624}

chrome/android/java/res/drawable/ic_sync_off_48dp.xml

@@ -13,7 +13,7 @@
 
     <path
         android:pathData="M20,30.5C25.799,30.5 30.5,25.799 30.5,20C30.5,14.201 25.799,9.5 20,9.5C14.201,9.5 9.5,14.201 9.5,20C9.5,25.799 14.201,30.5 20,30.5Z"
-        android:fillColor="@color/default_icon_color_secondary"/>
+        android:fillColor="@color/modern_grey_500"/>
     <path
         android:pathData="M18.7501,16.4687V15.1625C18.2501,15.2938 17.7813,15.5 17.3563,15.7625L18.2688,16.675C18.4251,16.6 18.5813,16.525 18.7501,16.4687ZM14.2876,15.8812L15.7626,17.3562C15.2813,18.1188 15.0001,19.025 15.0001,20C15.0001,21.3813 15.5688,22.625 16.4751,23.525L15.0001,25H18.7501V21.25L17.3501,22.65C16.6751,21.9687 16.2501,21.0375 16.2501,20C16.2501,19.375 16.4063,18.7875 16.6751,18.2687L21.7251,23.3187C21.5688,23.4 21.4126,23.475 21.2438,23.5312V24.8375C21.7438,24.7062 22.2126,24.5 22.6376,24.2375L24.1126,25.7125L24.9063,24.9188L15.0876,15.0875L14.2876,15.8812ZM25.0001,15H21.2501V18.75L22.6501,17.35C23.3251,18.0313 23.7501,18.9625 23.7501,20C23.7501,20.625 23.5938,21.2125 23.3251,21.7313L24.2376,22.6437C24.7188,21.8812 25.0001,20.975 25.0001,20C25.0001,18.6187 24.4313,17.375 23.5251,16.475L25.0001,15Z"
         android:fillColor="@color/default_bg_color"/>