[jmc8] merge request from master to jmc8 branch for JMC-7039, JMC-7088

[Guru Prasad H B]

Hi Marcus,

Please approve the merge request to “jmc8” release branch for (1) and (2) mentioned below :
1. JMC-7039: Timestamp granularity too coarse (https://github.com/openjdk/jmc/commit/7b1ae3e3da4757bf3b19bfc6c9c052bf086f343d)
2. JMC-7088: Show concurrent option showing lesser number of records.(https://github.com/openjdk/jmc/commit/bd35f0bda93be1f429c12f439c8c68afc146961b)

Thanks,
Guru