added Legacy feature tracking and unit testing

Author: kai-ion

src/aws-cpp-sdk-core/include/aws/core/client/UserAgent.h

@@ -32,8 +32,8 @@ enum class UserAgentFeature {
   ACCOUNT_ID_MODE_REQUIRED,
   RESOLVED_ACCOUNT_ID,
   GZIP_REQUEST_COMPRESSION,
+  CREDENTIALS_SIGV4_SIGNER,
   CREDENTIALS_ENV_VARS,
-  LEGACY_SIGV4_SIGNER,
 };
 
 class AWS_CORE_API UserAgent {

src/aws-cpp-sdk-core/source/auth/signer/AWSAuthV4Signer.cpp

@@ -84,7 +84,7 @@ bool AWSAuthV4Signer::SignRequestWithSigV4a(Aws::Http::HttpRequest& request, con
     Aws::Auth::CredentialsResolutionContext context;
     AWSCredentials credentials = GetCredentials(context, request.GetServiceSpecificParameters());
 
-    context.AddUserAgentFeature(Aws::Client::UserAgentFeature::LEGACY_SIGV4_SIGNER);
+    context.AddUserAgentFeature(Aws::Client::UserAgentFeature::CREDENTIALS_SIGV4_SIGNER);
 
     UpdateUserAgentWithCredentialFeatures(request, context);
     auto crtCredentials = Aws::MakeShared<Aws::Crt::Auth::Credentials>(v4AsymmetricLogTag,
@@ -344,7 +344,7 @@ bool AWSAuthV4Signer::SignRequest(Aws::Http::HttpRequest& request, const char* r
     Aws::Auth::CredentialsResolutionContext context;
     AWSCredentials credentials = GetCredentials(context, request.GetServiceSpecificParameters());
 
-    context.AddUserAgentFeature(Aws::Client::UserAgentFeature::LEGACY_SIGV4_SIGNER);
+    context.AddUserAgentFeature(Aws::Client::UserAgentFeature::CREDENTIALS_SIGV4_SIGNER);
 
     UpdateUserAgentWithCredentialFeatures(request, context);
 
@@ -478,7 +478,7 @@ bool AWSAuthV4Signer::PresignRequest(Aws::Http::HttpRequest& request, const char
     Aws::Auth::CredentialsResolutionContext context;
     AWSCredentials credentials = GetCredentials(context, request.GetServiceSpecificParameters());
 
-    context.AddUserAgentFeature(Aws::Client::UserAgentFeature::LEGACY_SIGV4_SIGNER);
+    context.AddUserAgentFeature(Aws::Client::UserAgentFeature::CREDENTIALS_SIGV4_SIGNER);
 
     UpdateUserAgentWithCredentialFeatures(request, context);
 
@@ -639,7 +639,7 @@ void AWSAuthV4Signer::UpdateUserAgentWithCredentialFeatures(Aws::Http::HttpReque
             case Aws::Client::UserAgentFeature::CREDENTIALS_ENV_VARS:
                 featureStr = "g";
                 break;
-            case Aws::Client::UserAgentFeature::LEGACY_SIGV4_SIGNER:
+            case Aws::Client::UserAgentFeature::CREDENTIALS_SIGV4_SIGNER:
                 featureStr = "MD";
                 break;
             default:

src/aws-cpp-sdk-core/source/client/UserAgent.cpp

@@ -42,8 +42,8 @@ const std::pair<UserAgentFeature, const char*> BUSINESS_METRIC_MAPPING[] = {
     {UserAgentFeature::ACCOUNT_ID_MODE_REQUIRED, "R"},
     {UserAgentFeature::RESOLVED_ACCOUNT_ID, "T"},
     {UserAgentFeature::GZIP_REQUEST_COMPRESSION, "L"},
+    {UserAgentFeature::CREDENTIALS_SIGV4_SIGNER, "MD"},
     {UserAgentFeature::CREDENTIALS_ENV_VARS, "g"},
-    {UserAgentFeature::LEGACY_SIGV4_SIGNER, "MD"},
 };
 
 Aws::String BusinessMetricForFeature(UserAgentFeature feature) {