Fix sending empty request when batch is empty

[senegalo]

Description

When finishBundle is called a call to createRequest to send any remaining elements in the bundle in a single gRPC request. In some corner cases we can end up sending empty batch requests (with no elements) like in the following:

• In the case where all the bundle can be satisfied from the cache
• in the case when the bundle size == batch size

Basically any time we reach the finishBundle and the batch queue is empty we send an empty batch request as we are not checking in createRequest if there are elements or not.

Changes

Only call createRequest in finishBundle if there are still element in the batch queue.

[codecov]

Codecov Report

Merging #5060 (fc5dd11) into main (47b254b) will not change coverage.
The diff coverage is n/a.

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