[NearbyShare] Fix styling for receive confirmation dialog.

This CL fixes two styling issues with the receive confirmation
dialog. 1) spacing between progress icon and dashed line
2) Fix outside margin for confirmation page contents.

Before Screenshot: https://screenshot.googleplex.com/4vDbAT4uWSdZsZJ.png
After Screenshot: https://screenshot.googleplex.com/rjHhgLqBRozaYKa.png

Fixed: 1156037
Change-Id: I034605dca9da7da016ad8da091e9c3c1ece16dfc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2593426Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Commit-Queue: Azeem Arshad <azeemarshad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#837428}

chrome/browser/resources/nearby_share/shared/nearby_progress.html

@@ -17,6 +17,7 @@
         line-height: 154%;
         overflow: hidden;
         text-align: center;
+        width: 116px;
       }
 
       #icon {

chrome/browser/resources/settings/chromeos/nearby_share_page/nearby_share_confirm_page.html

@@ -14,7 +14,7 @@
         display: flex;
         flex-direction: column;
         flex-grow: 1;
-        margin: 0 32px;
+        margin: 0 24px;
       }
 
       #connectionToken {