Reduce tray corner radius to 16

Ux requirement

Change-Id: If4d4e4320dc88d6d4380a7154cf105109834c3b2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1867629Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Ahmed Mehfooz <amehfooz@google.com>
Cr-Commit-Position: refs/heads/master@{#707893}

ash/system/tray/tray_constants.h

@@ -109,7 +109,7 @@ constexpr int kUnifiedNotificationCenterSpacing = 16;
 constexpr int kUnifiedTrayIconSize = 20;
 constexpr int kUnifiedTraySpacingBetweenIcons = 6;
 constexpr int kUnifiedTrayBatteryWidth = 10;
-constexpr int kUnifiedTrayCornerRadius = 20;
+constexpr int kUnifiedTrayCornerRadius = 16;
 constexpr int kUnifiedTrayContentPadding = 12;
 constexpr int kUnifiedTopShortcutSpacing = 16;
 constexpr int kUnifiedNotificationHiddenLineHeight = 20;