[fenix] For https://github.com/mozilla-mobile/fenix/issues/19307: Increased contrast ratio of chevron symbol in Collections (For Dark theme) (https://github.com/mozilla-mobile/fenix/pull/19377)

* For https://github.com/mozilla-mobile/fenix/issues/19307: Increased contrast ratio of chevron symbol in Collections (Dark Theme)

- Made a code change in collection_home_list_row.xml which fixes the colour of the chevron symbol in Dark theme

* Replaced android:src with app:srcCompat to pass Lint check

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

@@ -51,7 +51,7 @@
         android:layout_width="24dp"
         android:layout_height="24dp"
         android:layout_marginEnd="16dp"
-        android:background="@drawable/ic_chevron"
+        app:srcCompat="@drawable/ic_chevron"
         android:contentDescription="@string/tab_menu"
         app:layout_constraintBottom_toBottomOf="@id/collection_icon"
         app:layout_constraintEnd_toStartOf="@+id/collection_share_button"