[vcpkg] Fix incorrect handling of messages for permenantly disabled metrics. (#15636)

Fixes #15630

scripts/azure-pipelines/end-to-end-tests-dir/disable-metrics.ps1

@@ -41,6 +41,12 @@ try {
         throw "Environment variable did not disable metrics."
     }
 
+    # Also test that you get no message without --sendmetrics
+    $vcpkgOutput = Run-Vcpkg list
+    if ($vcpkgOutput -contains $metricsAreDisabledMessage) {
+        throw "Disabled metrics emit message even without --sendmetrics"
+    }
+
     if (-Not (Test-Metrics-Enabled '--no-disable-metrics')) {
         throw "Environment variable to disable metrics could not be overridden by switch."
     }

toolsrc/src/vcpkg.cpp

@@ -256,7 +256,7 @@ int main(const int argc, const char* const* const argv)
             metrics->set_send_metrics(*p);
         }
 
-        if (args.send_metrics.value_or(true) && !metrics->metrics_enabled())
+        if (args.send_metrics.value_or(false) && !metrics->metrics_enabled())
         {
             System::print2(System::Color::warning, "Warning: passed --sendmetrics, but metrics are disabled.\n");
         }