Update on "[quant] Add quantized::leaky_relu that takes scale/zero_po…

…int as input"

Summary:
#45593

Previously quantized leaky_relu does not require observation and just inherits
the quantization parameters from input, but that does not work very well in qat
This PR added a quantized::leaky_relu that has observation for output and it will
become the default leaky_relu that our quantization tools produce (eager/graph mode)

Test Plan:

Reviewers:

Subscribers:

Tasks:

Tags:

Differential Revision: [D24067681](https://our.internmc.facebook.com/intern/diff/D24067681)

[ghstack-poisoned]

aten/src/ATen/native/quantized/cpu/qrelu.cpp

@@ -174,6 +174,9 @@ class QLeakyRelu final {
  public:
   static Tensor run(Tensor self, Scalar negative_slope, bool inplace, double output_scale, int64_t output_zero_point) {
     // inplace argument is ignored now, TODO:support inplace
+    if (inplace) {
+      TORCH_WARN("inplace=True is not supported for quantized::leaky_relu yet");
+    }
     const auto qx = self.contiguous(self.suggest_memory_format());
     auto qy = at::_empty_affine_quantized(qx.sizes(),
       at::device(kCPU).dtype(self.scalar_type()),