input: Write a python function to filter array elements that start with the letter 'A'.
  assert filter_array_elements(["Apple", "Grape", "Banana", "Aeroplane"]) == ["Apple", "Aeroplane"]
  assert filter_array_elements(["Apricot", "Blueberry", "Avocado", "Cherry"]) == ["Apricot", "Avocado"]
  assert filter_array_elements(["Grapes", "Orange", "Apple", "Mango"]) == ["Apple"]
  assert filter_array_elements(["Banana", "Plum", "Peach", "Berry"]) == []
output: def filter_array_elements(arr):
      return [item for item in arr if item.startswith('A')]