[BEAM-6748] Account for synchronization interval when estimating amount of blocks in generated Avro test file. (#8015)
[BEAM-6748] Account for synchronization interval when estimating amount of blocks in generated Avro test file. (#8015)

* [BEAM-6748] Account for synchronization interval when estimating amount of blocks in generated Avro test file.

* Add an assertion to make sure the rest of the test makes sense.

chamikaramj/beam,lukecwik/incubator-beam,RyanSkraba/beam,robertwb/incubator-beam,apache/beam,robertwb/incubator-beam,apache/beam,chamikaramj/beam,RyanSkraba/beam,apache/beam,RyanSkraba/beam,chamikaramj/beam,lukecwik/incubator-beam,chamikaramj/beam,apache/beam,apache/beam,chamikaramj/beam,chamikaramj/beam,markflyhigh/incubator-beam,RyanSkraba/beam,robertwb/incubator-beam,chamikaramj/beam,chamikaramj/beam,markflyhigh/incubator-beam,lukecwik/incubator-beam,RyanSkraba/beam,robertwb/incubator-beam,robertwb/incubator-beam,lukecwik/incubator-beam,robertwb/incubator-beam,chamikaramj/beam,lukecwik/incubator-beam,apache/beam,apache/beam,RyanSkraba/beam,apache/beam,apache/beam,markflyhigh/incubator-beam,apache/beam,apache/beam,markflyhigh/incubator-beam,iemejia/incubator-beam,robertwb/incubator-beam,RyanSkraba/beam,markflyhigh/incubator-beam,lukecwik/incubator-beam,markflyhigh/incubator-beam,iemejia/incubator-beam,chamikaramj/beam,markflyhigh/incubator-beam,lukecwik/incubator-beam,robertwb/incubator-beam,lukecwik/incubator-beam,lukecwik/incubator-beam,lukecwik/incubator-beam,robertwb/incubator-beam,robertwb/incubator-beam