hg: jmc/jmc: JMC-5701: GC stall rule never reports OK result

[hdafgard at gmail.com]

Changeset: febe45d094b7
Author:    hdafgard <hdafgard at gmail.com>
Date:      2019-07-11 17:52 -0400
URL:       https://hg.openjdk.java.net/jmc/jmc/rev/febe45d094b7

JMC-5701: GC stall rule never reports OK result
Summary: Require GC events to be both unavailable and disabled to return a N/A result
Reviewed-by: hdafgard
Contributed-by: Florian David <florian.david at datadoghq.com>

! core/org.openjdk.jmc.flightrecorder.rules.jdk/src/main/java/org/openjdk/jmc/flightrecorder/rules/jdk/memory/GcStallRule.java
! core/tests/org.openjdk.jmc.flightrecorder.rules.jdk.test/src/test/resources/baseline/JfrRuleBaseline.xml