pubsublite.SubscriptionPartitionLoaderTest.addedResults flaky

This test has flaked several times in Java precommit. Might have been caused by https://github.com/apache/beam/pull/15418.

java.lang.AssertionError: SubscriptionPartitionLoader/MapElements/Map/ParMultiDo(Anonymous).output: Expected: iterable with items [<SubscriptionPartition\\{subscription=projects/3298749273/locations/europe-fake2-z/subscriptions/example-subscription, partition=Partition{value=0}}>, <SubscriptionPartition\\{subscription=projects/3298749273/locations/europe-fake2-z/subscriptions/example-subscription, partition=Partition{value=1}}>, <SubscriptionPartition\\{subscription=projects/3298749273/locations/europe-fake2-z/subscriptions/example-subscription, partition=Partition{value=2}}>, <SubscriptionPartition\\{subscription=projects/3298749273/locations/europe-fake2-z/subscriptions/example-subscription, partition=Partition{value=3}}>] in any order but: no item matches: <SubscriptionPartition{subscription=projects/3298749273/locations/europe-fake2-z/subscriptions/example-subscription, partition=Partition{value=3}}> in [<SubscriptionPartition\\{subscription=projects/3298749273/locations/europe-fake2-z/subscriptions/example-subscription, partition=Partition{value=0}}>, <SubscriptionPartition\\{subscription=projects/3298749273/locations/europe-fake2-z/subscriptions/example-subscription, partition=Partition{value=2}}>, <SubscriptionPartition\\{subscription=projects/3298749273/locations/europe-fake2-z/subscriptions/example-subscription, partition=Partition{value=1}}>]

https://ci-beam.apache.org/job/beam_PreCommit_Java_Cron/4499/testReport/junit/org.apache.beam.sdk.io.gcp.pubsublite/SubscriptionPartitionLoaderTest/addedResults/