fix: s2t demo app crashes (#610)

## Description

Changes:
- reorder data member declarations

### Introduces a breaking change?

- [ ] Yes
- [x] No

### Type of change

- [x] Bug fix (change which fixes an issue)
- [ ] New feature (change which adds functionality)
- [ ] Documentation update (improves or adds clarity to existing
documentation)
- [ ] Other (chores, tests, code style improvements etc.)

### Tested on

- [x] iOS
- [x] Android

### Checklist

- [x] I have performed a self-review of my code
- [x] I have commented my code, particularly in hard-to-understand areas
- [ ] I have updated the documentation accordingly
- [x] My changes generate no new warnings

Author: jakmro

packages/react-native-executorch/common/rnexecutorch/models/speech_to_text/SpeechToText.cpp

@@ -85,8 +85,6 @@ void SpeechToText::stream(std::shared_ptr<jsi::Function> callback,
         });
   };
 
-  this->resetStreamState();
-
   this->isStreaming = true;
   while (this->isStreaming) {
     if (!this->readyToProcess ||
@@ -102,14 +100,13 @@ void SpeechToText::stream(std::shared_ptr<jsi::Function> callback,
 
   std::string committed = this->processor->finish();
   nativeCallback(committed, "", true);
+
+  this->resetStreamState();
 }
 
 void SpeechToText::streamStop() { this->isStreaming = false; }
 
 void SpeechToText::streamInsert(std::span<float> waveform) {
-  if (!this->isStreaming) {
-    throw std::runtime_error("Streaming is not started");
-  }
   this->processor->insertAudioChunk(waveform);
   this->readyToProcess = true;
 }

packages/react-native-executorch/common/rnexecutorch/models/speech_to_text/SpeechToText.h

@@ -29,13 +29,13 @@ class SpeechToText {
   void streamInsert(std::span<float> waveform);
 
 private:
+  std::shared_ptr<react::CallInvoker> callInvoker;
   std::unique_ptr<BaseModel> encoder;
   std::unique_ptr<BaseModel> decoder;
   std::unique_ptr<TokenizerModule> tokenizer;
   std::unique_ptr<asr::ASR> asr;
 
   // Stream
-  std::shared_ptr<react::CallInvoker> callInvoker;
   std::unique_ptr<stream::OnlineASRProcessor> processor;
   bool isStreaming;
   bool readyToProcess;