Specifies the search result mode. If unspecified, the search result
mode is based on
[DataStore.DocumentProcessingConfig.chunking_config][]:
If [DataStore.DocumentProcessingConfig.chunking_config][] is
specified, it defaults to CHUNKS.
Otherwise, it defaults to DOCUMENTS.
Values:
SEARCH_RESULT_MODE_UNSPECIFIED (0):
Default value.
DOCUMENTS (1):
Returns documents in the search result.
CHUNKS (2):
Returns chunks in the search result. Only available if the
[DataStore.DocumentProcessingConfig.chunking_config][] is
specified.