Return or throw HRESULTs from published samples

.github/workflows/dotnet.yml

@@ -243,7 +243,8 @@ jobs:
  sleep -Seconds 2;
  $process.CloseMainWindow() | Out-Null;
  $process.WaitForExit();
- $process.ExitCode
+ if ($process.ExitCode -lt 0) { throw $process.ExitCode; }
+ return $process.ExitCode;
 
  # Upload the binary (to track binary size trends)
  - if: matrix.platform == 'x64'
@@ -271,7 +272,8 @@ jobs:
  sleep -Seconds 2;
  $process.CloseMainWindow() | Out-Null;
  $process.WaitForExit();
- $process.ExitCode
+ if ($process.ExitCode -lt 0) { throw $process.ExitCode; }
+ return $process.ExitCode;
 
  # Upload the binary again (with a different name)
  - if: matrix.platform == 'x64'
@@ -297,7 +299,8 @@ jobs:
  sleep -Seconds 2;
  $process.CloseMainWindow() | Out-Null;
  $process.WaitForExit();
- $process.ExitCode
+ if ($process.ExitCode -lt 0) { throw $process.ExitCode; }
+ return $process.ExitCode;
 
  # Download the NuGet packages generated in the previous job and use them
  # to build and run the sample project referencing them. This is used as