HHH-8401 : Unit test fixes

(cherry picked from commit 45511f10ae58e9460fd09e6da5c33b1332494cbf)

Conflicts:
	hibernate-core/src/test/java/org/hibernate/test/temporal/TimestampPropertyTest.java
	hibernate-envers/src/test/java/org/hibernate/envers/test/integration/strategy/ValidityAuditStrategyRevEndTsTest.java
HHH-8401 : Support fractional seconds on MySQL 5.7 (tweak test cases for 4.2)