remove struct SecondaryHostReplicaStatus, to simplify context use (#1913)

# Pull Request Checklist

Please leverage this checklist as a reminder to address commonly occurring feedback when submitting a pull request to make sure your PR can be reviewed quickly:

See the detailed list in the [contributing guide](https://github.com/Azure/azure-sdk-for-cpp/blob/master/CONTRIBUTING.md#pull-requests).

- [x] [C++ Guidelines](https://azure.github.io/azure-sdk/cpp_introduction.html)
- [x] Doxygen docs
- [x] Unit tests
- [x] No unwanted commits/changes
- [x] Descriptive title/description
  - [x] PR is single purpose
  - [x] Related issue listed
- [x] Comments in source
- [x] No typos
- [x] Update changelog
- [x] Not work-in-progress
- [x] External references or docs updated
- [x] Self review of PR done
- [x] Any breaking changes?

sdk/storage/azure-storage-common/inc/azure/storage/common/storage_switch_to_secondary_policy.hpp

@@ -13,15 +13,9 @@ namespace Azure { namespace Storage { namespace _internal {
   static constexpr const char* SecondaryHostReplicaStatusKey
       = "AzureSdkStorageSecondaryHostReplicaStatusKey";
 
-  struct SecondaryHostReplicaStatus
-  {
-    bool replicated = true;
-  };
-
   inline Azure::Core::Context WithReplicaStatus(const Azure::Core::Context& context)
   {
-    return context.WithValue(
-        SecondaryHostReplicaStatusKey, std::make_unique<SecondaryHostReplicaStatus>());
+    return context.WithValue(SecondaryHostReplicaStatusKey, std::make_shared<bool>(true));
   }
 
   class StorageSwitchToSecondaryPolicy : public Azure::Core::Http::Policies::HttpPolicy {

sdk/storage/azure-storage-common/src/storage_switch_to_secondary_policy.cpp

@@ -10,17 +10,15 @@ namespace Azure { namespace Storage { namespace _internal {
       Azure::Core::Http::Policies::NextHttpPolicy nextHttpPolicy,
       const Azure::Core::Context& ctx) const
   {
-    SecondaryHostReplicaStatus* replicaStatus = nullptr;
+    std::shared_ptr<bool> replicaStatus;
     if (ctx.HasKey(SecondaryHostReplicaStatusKey))
     {
-      replicaStatus
-          = ctx.Get<std::unique_ptr<SecondaryHostReplicaStatus>>(SecondaryHostReplicaStatusKey)
-                .get();
+      replicaStatus = ctx.Get<std::shared_ptr<bool>>(SecondaryHostReplicaStatusKey);
     }
 
     bool considerSecondary = (request.GetMethod() == Azure::Core::Http::HttpMethod::Get
                               || request.GetMethod() == Azure::Core::Http::HttpMethod::Head)
-        && !m_secondaryHost.empty() && replicaStatus && replicaStatus->replicated;
+        && !m_secondaryHost.empty() && replicaStatus && *replicaStatus;
 
     if (considerSecondary && Azure::Core::Http::Policies::RetryPolicy::GetRetryNumber(ctx) > 0)
     {
@@ -42,7 +40,7 @@ namespace Azure { namespace Storage { namespace _internal {
             || response->GetStatusCode() == Core::Http::HttpStatusCode::PreconditionFailed)
         && request.GetUrl().GetHost() == m_secondaryHost)
     {
-      replicaStatus->replicated = false;
+      *replicaStatus = false;
       // switch back
       request.GetUrl().SetHost(m_primaryHost);
       response = nextHttpPolicy.Send(request, ctx);