[NTP] Fix selected tile state for custom bgs

The new styling should only apply to the new
customization menu.

Bug: 962353
Change-Id: I8f9ff9dc925a58c9403576c0d33b845d8673d523
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1609601Reviewed-by: Gayane Petrosyan <gayane@chromium.org>
Commit-Queue: Kyle Milka <kmilka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#659127}

chrome/browser/resources/local_ntp/local_ntp.css

@@ -1099,7 +1099,7 @@ html[dir=rtl] #menu-back {
   width: 100%;
 }
 
-.bg-sel-tile .selected-circle {
+#customization-menu .bg-sel-tile .selected-circle {
   height: 20px;
   left: initial;
   right: 10px;
@@ -1107,12 +1107,12 @@ html[dir=rtl] #menu-back {
   width: 20px;
 }
 
-html[dir=rtl] .bg-sel-tile .selected-circle {
+html[dir=rtl] #customization-menu .bg-sel-tile .selected-circle {
   left: 10px;
   right: initial;
 }
 
-.bg-sel-tile .selected-check {
+#customization-menu .bg-sel-tile .selected-check {
   height: 24px;
   left: initial;
   right: 0;
@@ -1120,7 +1120,7 @@ html[dir=rtl] .bg-sel-tile .selected-circle {
   width: 24px;
 }
 
-html[dir=rtl] .bg-sel-tile .selected-check {
+html[dir=rtl] #customization-menu .bg-sel-tile .selected-check {
   left: 0;
   right: initial;
 }