Make perf threshold fail on a certain percentage and not hard comparison <=

[Karm]

Test suite reports how big is the difference between a value and its threshold when it fails:

org.opentest4j.AssertionFailedError: 
Application JFR_SMOKE_BUILDER_IMAGE in mode jvm_jfr took 7095 ms to finish, 
which is over 6924 ms threshold by 2%.
 ==> expected: <true> but was: <false>

The decision whether to fail a test should be made based on the percentage, i.e. 2% should not fail the test, rather than on a simple comparison of value to its threshold.