fix: LLM - Fixed the InlineContext grounding source

PiperOrigin-RevId: 615887256

vertexai/language_models/_language_models.py

@@ -1036,9 +1036,9 @@ def _to_grounding_source_dict(self) -> Dict[str, Any]:
             "sources": [
                 {
                     "type": self._type,
+                    "inlineContext": self.inline_context,
                 }
             ],
-            "inlineContext": self.inline_context,
         }