Use lower-case for the default value of bes_upload_mode.

Enum converter and bash autocompletion accept lower-case so we change it here to make it more consistent.

PiperOrigin-RevId: 243986416
diff --git a/src/main/java/com/google/devtools/build/lib/buildeventservice/BuildEventServiceOptions.java b/src/main/java/com/google/devtools/build/lib/buildeventservice/BuildEventServiceOptions.java
index eda45ce..ed22d50 100644
--- a/src/main/java/com/google/devtools/build/lib/buildeventservice/BuildEventServiceOptions.java
+++ b/src/main/java/com/google/devtools/build/lib/buildeventservice/BuildEventServiceOptions.java
@@ -128,7 +128,7 @@
 
   @Option(
       name = "bes_upload_mode",
-      defaultValue = "WAIT_FOR_UPLOAD_COMPLETE",
+      defaultValue = "wait_for_upload_complete",
       converter = BesUploadModeConverter.class,
       documentationCategory = OptionDocumentationCategory.UNDOCUMENTED,
       effectTags = {OptionEffectTag.EAGERNESS_TO_EXIT},