EfficientNetV2 does not match google implementation
Hi,
I may be wrong, but checking the efficientnetv2 implementation I think there is a difference with the [google one](https://github.com/google/automl/blob/387d5ddb92bb8fbbec4b012e5636a81ea65fffda/efficientnetv2/effnetv2_model.py)
The  ["survival_probability"](https://github.com/keras-team/keras/blob/d8fcb9d4d4dad45080ecfdd575483653028f8eda/keras/applications/efficientnet_v2.py#L990) is defined as `survival_probability=drop_connect_rate * b / blocks` but b is set to zero, while according to the [google implementation](https://github.com/google/automl/blob/387d5ddb92bb8fbbec4b012e5636a81ea65fffda/efficientnetv2/effnetv2_model.py#L619) it should increase with the "number" of the block.

I think that line should be replaced with:
`survival_probability=drop_connect_rate * i / blocks` 
where i is the counter of the for loop

diff --git a/keras/applications/efficientnet_v2.py b/keras/applications/efficientnet_v2.py
index a329ed23e1..6a1b5be8d0 100644
--- a/keras/applications/efficientnet_v2.py
+++ b/keras/applications/efficientnet_v2.py
@@ -991,6 +991,7 @@ def EfficientNetV2(
           name="block{}{}_".format(i + 1, chr(j + 97)),
           **args,
       )(x)
+      b += 1
 
   # Build top
   top_filters = round_filters(
['keras/applications/efficientnet_v2.py']