Update a2a/src/main/java/com/google/adk/a2a/converters/PartConverter.java

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: fsonntag

a2a/src/main/java/com/google/adk/a2a/converters/PartConverter.java

@@ -32,7 +32,7 @@ public final class PartConverter {
   // ADK metadata key prefix (must match Python's ADK_METADATA_KEY_PREFIX)
   private static final String ADK_METADATA_KEY_PREFIX = "adk_";
 
-  // Constants for metadata types (prefixed with adk_ to match Python)
+// Constants for metadata keys (prefixed with adk_ to match Python)
   public static final String A2A_DATA_PART_METADATA_TYPE_KEY = ADK_METADATA_KEY_PREFIX + "type";
   public static final String A2A_DATA_PART_METADATA_IS_LONG_RUNNING_KEY =
       ADK_METADATA_KEY_PREFIX + "is_long_running";