Java precommit Samza tests opening RocksDB flaky

org.apache.beam.runners.samza.runtime.SamzaTimerInternalsFactoryTest.testProcessingTimeTimers and 
org.apache.beam.runners.samza.runtime.SamzaTimerInternalsFactoryTest.testRestore fail with exception: 

org.apache.samza.SamzaException: Error opening RocksDB store beamStore at location /tmp/store2

...

Caused by: org.rocksdb.RocksDBException: Can't access /000359.sst: IO error: while stat a file for size: /tmp/store2/000359.sst: No such file or directory Can't access /000356.sst: IO error: while stat a file for size: /tmp/store2/000356.sst: No such file or directory Can't access /000354.sst: IO error: while stat a file for size: /tmp/store2/000354.sst: No such file or directory

Example failures: https://builds.apache.org/job/beam_PreCommit_Java_Commit/6896/

https://builds.apache.org/job/beam_PreCommit_Java_Commit/6906/