LoggerFactory does not work while using SpannerMigrationCommandExecutor

(Copied from other repository)

Here is sample of my log provider:

```c#
public class MyLoggerProvider : ILoggerProvider
{
public ILogger CreateLogger(string categoryName)
{
return new MyLogger();
}

public void Dispose()
{ }

private class MyLogger : ILogger
{
public bool IsEnabled(LogLevel logLevel)
{
return true;
}

public void Log(LogLevel logLevel, EventId eventId, TState state, Exception exception, Func formatter)
{
File.AppendAllText(@"C:\temp\log.txt", formatter(state, exception));
Console.WriteLine(formatter(state, exception));
}

public IDisposable BeginScope(TState state)
{
return null;
}
}
}
```

Configure logger:

```C#
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
if (!optionsBuilder.IsConfigured)
{
optionsBuilder.UseSpanner("Data Source=projects/appdev-soda-spanner-staging/instances/orm-test-instance/databases/test_migration_db_4");
}

var lf = new LoggerFactory();
lf.AddProvider(new MyLoggerProvider());
optionsBuilder.UseLoggerFactory(lf);
}
```

In case of removing `SpannerMigrationCommandExecutor` from service collection it loges as expected.