input: Write a function to calculate the average of the elements in a 2-dimensional array and return the average rounded to two decimal places. If the matrix is empty or contains only empty lists, return 0.
  assert averageMatrix([[3, 2, 6], [8, 5, 9], [4, 7, 1]])==5.00
  assert averageMatrix([[1, 2], [3, 4]])==2.50
  assert averageMatrix([[1], [2], [3], [4]])==2.50
  assert averageMatrix([[1, 2, 3]])==2.00
  assert averageMatrix([])==0
  assert averageMatrix([[], [], []])==0
output: def averageMatrix(matrix):
      if not matrix or all(len(row) == 0 for row in matrix):
          return 0
      total_sum = sum(sum(row) for row in matrix)
      total_count = sum(len(row) for row in matrix)
      return round(total_sum / total_count, 2)