fix initial logeventlevel (#1880)

Co-authored-by: Cijo Thomas <cithomas@microsoft.com>

src/OpenTelemetry/Internal/SelfDiagnosticsConfigRefresher.cs

@@ -58,7 +58,7 @@ namespace OpenTelemetry.Internal
         private string logDirectory;  // Log directory for log files
         private int logFileSize;  // Log file size in bytes
         private long logFilePosition;  // The logger will write into the byte at this position
-        private EventLevel logEventLevel;
+        private EventLevel logEventLevel = (EventLevel)(-1);
 
         public SelfDiagnosticsConfigRefresher()
         {