Describe the current behavior / 问题描述 (Mandatory / 必填)

修改了cell中的一个属性的值, 在construct中需要使用这个属性控制if else, 但是值却并没有正确的被修改

Environment / 环境信息 (Mandatory / 必填)

• Hardware Environment(Ascend/GPU/CPU) / 硬件环境: Ascend

• Software Environment / 软件环境 (Mandatory / 必填):
  -- MindSpore version (e.g., 1.7.0.Bxxx) : 2.0 beta
  -- Python version (e.g., Python 3.7.5) : Python 3.7.5
  -- OS platform and distribution (e.g., Linux Ubuntu 16.04): eulor 2.8
  -- GCC/Compiler version (if compiled from source):

• Excute Mode / 执行模式 (Mandatory / 必填)(PyNative/Graph):

Please delete the mode not involved / 请删除不涉及的模式:

/mode graph

Steps to reproduce the issue / 重现步骤 (Mandatory / 必填)

import numpy as np
from mindspore import nn, Tensor
from mindspore import context


class Flag(nn.Cell):

    def __init__(self):
        super().__init__(auto_prefix=False)
        self.is_first_iteration = True

    def construct(self, x):

        if self.is_first_iteration:
            print('is first iteration', self.is_first_iteration)
        else:
            print('is not first iteration', self.is_first_iteration)

        return x


context.set_context(
    mode=context.GRAPH_MODE,
    device_target="Ascend",
    device_id=7)

network = Flag()
input0 = Tensor(np.arange(10))
input1 = Tensor(np.arange(20))

network.add_flags_recursive(is_first_iteration=True)
network(input0)

network.add_flags_recursive(is_first_iteration=False)
network(input0)

network(input1)

Describe the expected behavior / 预期结果 (Mandatory / 必填)

is first iteration
Tensor(shape=[], dtype=Bool, value=True)

is not first iteration
Tensor(shape=[], dtype=Bool, value=False)

is not first iteration
Tensor(shape=[], dtype=Bool, value=False)

Related log / screenshot / 日志 / 截图 (Mandatory / 必填)