[ET-VK] Moving device capabilities check to DispatchNode and PrepackNode ctor.

The changes in this diff move the device capabilities check from the encode method to the constructor of DispatchNode and PrepackNode classes.

Differential Revision: [D74481839](https://our.internmc.facebook.com/intern/diff/D74481839/)

ghstack-source-id: 283053996
Pull Request resolved: #10785

Author: trivedivivek

backends/vulkan/runtime/graph/ops/DispatchNode.cpp

@@ -33,6 +33,7 @@ DispatchNode::DispatchNode(
       spec_vars_(spec_vars),
       push_constants_(push_constants) {
   graph.update_descriptor_counts(shader, /*execute = */ true);
+  graph.context()->check_device_capabilities(shader_);
 }
 
 void DispatchNode::encode(ComputeGraph* graph) {
@@ -42,8 +43,6 @@ void DispatchNode::encode(ComputeGraph* graph) {
   api::Context* const context = graph->context();
   vkapi::PipelineBarrier pipeline_barrier{};
 
-  context->check_device_capabilities(shader_);
-
   std::unique_lock<std::mutex> cmd_lock = context->dispatch_lock();
 
   std::array<uint8_t, kMaxPushConstantSize> push_constants_data;

backends/vulkan/runtime/graph/ops/PrepackNode.cpp

@@ -45,6 +45,7 @@ PrepackNode::PrepackNode(
       push_constants_(push_constants) {
   graph.update_descriptor_counts(shader, /*execute = */ false);
   graph.update_descriptor_counts(noop_shader_, /*execute = */ false);
+  graph.context()->check_device_capabilities(shader_);
 }
 
 api::StagingBuffer PrepackNode::create_staging_buffer(ComputeGraph* graph) {
@@ -70,8 +71,6 @@ api::StagingBuffer PrepackNode::create_staging_buffer(ComputeGraph* graph) {
 void PrepackNode::encode(ComputeGraph* graph) {
   api::Context* const context = graph->context();
 
-  context->check_device_capabilities(shader_);
-
   vTensorPtr packed = graph->get_tensor(packed_);
   api::StagingBuffer staging = create_staging_buffer(graph);