Created by: zhupengyang
- fix input shape of op tests for scatter, sequence_pad, sequence_unpad, expand, pad, pad_constant_like, norm, bilinear_tensor_product, flatten2, im2sequence, unpool, cos_sim, strided_slice, flatten, elementwise_min, abs, acos
- fix https://github.com/PaddlePaddle/Paddle/pull/21391/files#r356043791