During zuul testing, Elasticsearch would not always have the memory available
to handle the logs generated on startup by system services in real time. This
would cause test failures due to Elasticsearch buffering, which resulted in
unusually large data transfers. The testing Elasticsearch JVM heap size has
been bumped from 512mb to 1024mb to try and prevent these issues during testing.
This change only affects the CI tests.
Change-Id: I93c57fd0bcf62d5da7f7472dafef75375a63f07f