For #14619: Show half a tab top offset when scrolling to selected tab.

app/src/main/java/org/mozilla/fenix/tabtray/TabTrayView.kt

@@ -652,13 +652,15 @@ class TabTrayView(
 
             // We offset the tab index by the number of items in the other adapters.
             // We add the offset, because the layoutManager is initialized with `reverseLayout`.
-            // We also add 1 to display the tab item above the selected browser tab.
             val recyclerViewIndex = selectedBrowserTabIndex +
                 collectionsButtonAdapter.itemCount +
-                syncedTabsController.adapter.itemCount +
-                1
+                syncedTabsController.adapter.itemCount
 
             layoutManager?.scrollToPosition(recyclerViewIndex)
+            smoothScrollBy(
+                0,
+                - resources.getDimensionPixelSize(R.dimen.tab_tray_tab_item_height) / 2
+            )
         }
     }
 

app/src/main/res/layout/tab_tray_item.xml

@@ -7,7 +7,7 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:id="@+id/tab_item"
     android:layout_width="match_parent"
-    android:layout_height="88dp"
+    android:layout_height="@dimen/tab_tray_tab_item_height"
     android:clickable="true"
     android:focusable="true"
     android:foreground="?android:selectableItemBackground">

app/src/main/res/values/dimens.xml

@@ -171,6 +171,7 @@
 
     <!-- Tabs Tray -->
     <dimen name="tab_tray_top_offset">40dp</dimen>
+    <dimen name="tab_tray_tab_item_height">88dp</dimen>
     <dimen name="tab_tray_list_item_thumbnail_width">92dp</dimen>
     <dimen name="tab_tray_list_item_thumbnail_height">72dp</dimen>
     <dimen name="tab_tray_grid_item_thumbnail_width">156dp</dimen>