[Autofill Assistant] Remove assistant color alias for light grey.

Bug: 806868
Change-Id: I7fcccc58ac9e397c5809a06d5bb407600ce73fe2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1844960Reviewed-by: Jordan Demeulenaere <jdemeulenaere@chromium.org>
Commit-Queue: Sandro Maggi <sandromaggi@google.com>
Cr-Commit-Position: refs/heads/master@{#703316}

chrome/android/features/autofill_assistant/java/res/drawable/autofill_assistant_swipe_indicator.xml

@@ -5,7 +5,7 @@
 <shape
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:shape="rectangle">
-  <solid android:color="@color/autofill_assistant_light_grey"/>
+  <solid android:color="@color/modern_grey_300"/>
   <corners android:radius="2dp"/>
   <size android:height="4dp" android:width="36dp"/>
 </shape>

chrome/android/features/autofill_assistant/java/res/values-v17/colors.xml

@@ -5,11 +5,10 @@
 
 <resources>
     <!--
-    TODO(crbuc.com/806868): Use Chrome approved colors and remove this.
+    TODO(crbug.com/806868): Use Chrome approved colors and remove this.
 
     Please see src/ui/android/java/res/values/colors.xml for the shared common colors.
     -->
-    <color name="autofill_assistant_light_grey">@color/modern_grey_300</color>
     <color name="autofill_assistant_light_blue">#E9F0FD</color>
     <color name="autofill_assistant_actions_shadow_color">#40CCCCCC</color>
 </resources>