(Part 2.5) Use new socket schema in ValueMetricProducer_test

First CL at ag/10697747. Sending ValueMetricProducer_test as multiple CLs to retain diff and make
it easier to review.

Updates from TestEmptyDataResetsBase_onConditionChanged to TestInvalidBucketWhenPullFailed

Test: bit statsd_test:*
Bug: 149590301
Change-Id: I915b47e086ee5065eaa71094b83d2b271ce847b7