Update base for Update on "[ET][EZ] Enable operator<< for Half tensor data"

Useful for debugging `Half` i.e. `fp16` models, when we have `EValue`s that are `Half` dtype and we do the following:
```
std::cout << "===== INPUT =====" << std::endl;
for (EValue& v : inputs) {
  std::cout << v << std::endl;
}

std::cout << "===== OUTPUT =====" << std::endl;
for (EValue& v : outputs) {
  std::cout << v << std::endl;
}
```

## Before
```
===== INPUT =====
tensor(sizes=[1, 3, 96, 72], [<unhandled scalar type 5>])
===== OUTPUT =====
tensor(sizes=[1, 2, 96, 72], [<unhandled scalar type 5>])
```

## After
```
===== INPUT =====
tensor(sizes=[1, 3, 96, 72], [0.279785, 0.271484, 0.364746, ..., 0.150391, 0.836426, 0.019043])
===== OUTPUT =====
tensor(sizes=[1, 2, 96, 72], [18.2344, -10.0938, 1.35059, ..., -33.6875, 4.07422, -22.5312])
```

Differential Revision: [D57977366](https://our.internmc.facebook.com/intern/diff/D57977366/)

[ghstack-poisoned]

Author: jorgep31415

backends/vulkan/runtime/graph/ops/glsl/avg_pool2d.glsl

@@ -9,7 +9,8 @@
 #version 450 core
 
 #define PRECISION ${PRECISION}
-#define FLT_MIN -3.402823466e+38
+
+#define VEC4_T ${texel_type(DTYPE)}
 
 #include "indexing_utils.h"
 
@@ -36,7 +37,7 @@ void main() {
   const ivec2 start = max(ivec2(0), ipos);
   const ivec2 end = min(ipos + kernel_size, ivec2(in_sizes.xy));
 
-  vec4 sum = vec4(0);
+  VEC4_T sum = VEC4_T(0);
   for (int y = start.y; y < end.y; ++y) {
     for (int x = start.x; x < end.x; ++x) {
       sum += texelFetch(t_in, ivec3(x, y, pos.z), 0);

backends/vulkan/runtime/graph/ops/glsl/avg_pool2d.yaml

@@ -13,5 +13,6 @@ avg_pool2d:
     DTYPE:
       - VALUE: half
       - VALUE: float
+      - VALUE: int
   shader_variants:
     - NAME: avg_pool2d