input: Write a python function to check if a given activity belongs to a specific category.
  assert is_activity_in_category('Coding', 'Work') == True
  assert is_activity_in_category('Gaming', 'Leisure') == True
  assert is_activity_in_category('Meeting', 'Work') == True
  assert is_activity_in_category('Cooking', 'Leisure') == False
output: def is_activity_in_category(activity, category):
      categories = {
          'Work': ['Coding', 'Meeting', 'Emailing', 'Planning'],
          'Leisure': ['Gaming', 'Reading', 'Traveling', 'Watching TV']
      }
      return activity in categories.get(category, [])