show the wrong file format (#7498)

Author: zeitlinger

sdk-extensions/incubator/src/main/java/io/opentelemetry/sdk/extension/incubator/fileconfig/OpenTelemetryConfigurationFactory.java

@@ -34,7 +34,7 @@ public OpenTelemetrySdk create(
     String fileFormat = model.getFileFormat();
     if (fileFormat == null || !SUPPORTED_FILE_FORMATS.matcher(fileFormat).matches()) {
       throw new DeclarativeConfigException(
-          "Unsupported file format. Supported formats include 0.4, 1.0*");
+          "Unsupported file format '" + fileFormat + "'. Supported formats include 0.4, 1.0*");
     }
     // TODO(jack-berg): log warning if version is not exact match, which may result in unexpected
     // behavior for experimental properties.

sdk-extensions/incubator/src/test/java/io/opentelemetry/sdk/extension/incubator/fileconfig/OpenTelemetryConfigurationFactoryTest.java

@@ -92,7 +92,8 @@ void create_FileFormat(String fileFormat, boolean isValid) {
       assertThatThrownBy(
               () -> OpenTelemetryConfigurationFactory.getInstance().create(model, context))
           .isInstanceOf(DeclarativeConfigException.class)
-          .hasMessage("Unsupported file format. Supported formats include 0.4, 1.0*");
+          .hasMessageMatching(
+              "Unsupported file format '.+'\\. Supported formats include 0\\.4, 1\\.0\\*");
     }
   }