Values:
GROUNDING_SCORE_BUCKET_UNSPECIFIED (0):
Score not specified.
VERY_LOW (1):
We have very low confidence that the answer
is grounded.
LOW (3):
We have low confidence that the answer is
grounded.
MEDIUM (4):
We have medium confidence that the answer is
grounded.
HIGH (5):
We have high confidence that the answer is
grounded.
VERY_HIGH (6):
We have very high confidence that the answer
is grounded.