[SharingHub] Make divider full width

Make the divider take up the full width of the bottom sheet.

Bug: 1152646
Change-Id: I5aae6100e6e9fe3b66d9a49a9451dd8e1c28b972
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2563434
Commit-Queue: Kyle Milka <kmilka@chromium.org>
Commit-Queue: Matthew Jones <mdjones@chromium.org>
Auto-Submit: Kyle Milka <kmilka@chromium.org>
Reviewed-by: Matthew Jones <mdjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#832001}

chrome/android/java/res/layout/share_sheet_content.xml

@@ -89,8 +89,6 @@
       android:id="@+id/share_sheet_divider"
       android:background="@color/divider_line_bg_color"
       android:layout_height="1dp"
-      android:layout_marginLeft="16dp"
-      android:layout_marginRight="16dp"
       android:layout_width="match_parent"
       android:visibility="gone" />