Fix the height of NotificationContentView when there's no actions but bubble button

Added margin dynamic update for the condition when a NotificationContentView has bubble button but no actions

Bug: 244522899
Test: Visual:
1. Mock a message notification that has bubble button but no actions, there shouldn't be a 20dp margin between notification_action_list_margin_target and actions_container.
2. Mock a message notification that has bubble button and actions, there shouldn't be a 20dp margin between notification_action_list_margin_target and actions_container.
3. Mock a message notification that has no bubble button or actions, notification_action_list_margin_target should have a 20dp bottom margin.
Change-Id: Ie834309872c786dcf120023e7449099ee415e38e