Fix bug of abs_double_grad in eager mode for kunlun, test=kunlun (#47722)

paddle/phi/api/yaml/legacy_backward.yaml

@@ -7,8 +7,6 @@
     param : [x]
   kernel :
     func : abs_double_grad
-  data_transform:
-    skip_transform : grad_x_grad
 
 - backward_op : abs_grad
   forward : abs (Tensor x) -> Tensor(out)

paddle/phi/kernels/cpu/abs_grad_kernel.cc

@@ -41,4 +41,6 @@ PD_REGISTER_KERNEL(abs_double_grad,
                    int,
                    int64_t,
                    complex<float>,
-                   complex<double>) {}
+                   complex<double>) {
+  kernel->InputAt(1).SetDataType(phi::dtype::ToReal(kernel_key.dtype()));
+}

paddle/phi/kernels/gpu/abs_grad_kernel.cu

@@ -45,4 +45,6 @@ PD_REGISTER_KERNEL(abs_double_grad,
                    int64_t,
                    phi::dtype::float16,
                    complex<float>,
-                   complex<double>) {}
+                   complex<double>) {
+  kernel->InputAt(1).SetDataType(phi::dtype::ToReal(kernel_key.dtype()));
+}