[NTP] Update darkmode selected state in the RP

Change the background color in the selected state for
RP tiles.

backgrounds screenshot: http://screen/nM89uUTB1eA
shortcuts screenshot: http://screen/26wy2mn4R3n

Bug: 937570
Change-Id: I7466d265da0081c9d4489f159ac8b604332e319f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1652742Reviewed-by: Kristi Park <kristipark@chromium.org>
Commit-Queue: Kyle Milka <kmilka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#668590}

chrome/browser/resources/local_ntp/customize.js

@@ -645,8 +645,8 @@ customize.richerPicker_selectTile = function(tile) {
   const selectedCheck = document.createElement('div');
   selectedCircle.classList.add(customize.CLASSES.SELECTED_CIRCLE);
   selectedCheck.classList.add(customize.CLASSES.SELECTED_CHECK);
-  selectedCircle.appendChild(selectedCheck);
   tile.appendChild(selectedCircle);
+  tile.appendChild(selectedCheck);
 };
 
 /**
@@ -1579,4 +1579,4 @@ customize.loadColorTiles = function() {
     $(customize.IDS.COLORS_MENU).appendChild(tile);
   }
   customize.colorMenuLoaded = true;
-};
+};
\ No newline at end of file

chrome/browser/resources/local_ntp/local_ntp.css

@@ -1071,6 +1071,11 @@ html[darkmode=true] #colors-menu .bg-sel-tile-title {
   background-color: rgba(var(--GB900-rgb), .08);
 }
 
+html[darkmode=true] #backgrounds-default.selected,
+html[darkmode=true] #backgrounds-image-menu .bg-sel-tile-bg.selected {
+  background-color: rgba(var(--GB200-rgb), .5);
+}
+
 #backgrounds-upload.bg-sel-tile-bg {
   background-color: white;
   border: 1px solid rgb(var(--GG300-rgb));
@@ -1171,13 +1176,13 @@ html[dir=rtl] #customization-menu .bg-sel-tile .selected-circle {
 #customization-menu .bg-sel-tile .selected-check {
   height: 24px;
   left: initial;
-  right: 0;
-  top: 0;
+  right: 9px;
+  top: 7px;
   width: 24px;
 }
 
 html[dir=rtl] #customization-menu .bg-sel-tile .selected-check {
-  left: 0;
+  left: 9px;
   right: initial;
 }
 
@@ -1331,13 +1336,14 @@ html[dir=rtl] .sh-option-image .selected-circle {
 }
 
 .sh-option-image .selected-check {
-  left: -2px;
-  top: -2px;
+  left: initial;
+  right: 32px;
+  top: 6px;
 }
 
 html[dir=rtl] .sh-option-image .selected-check {
-  left: 0;
-  right: -2px;
+  left: 32px;
+  right: initial;
 }
 
 .sh-option-title {