RFR: JMC-7539: Ensure installCore respects avoiding JDP tests

[Martin Skarsaune]

As 

> JDPClientTest.testChangePacket:95
> JDPClientTest.testJDPClient:73
> JDPJMXTest.testJDPClient:71

Now reside in common, installCore should skip JDP multicast test when the build file has been called with the flag to avoid JDP multicast tests

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Commit messages:
 - JMC-7539: Ensure installCore respects avoiding JDP tests

Changes: https://git.openjdk.org/jmc/pull/611/files
  Webrev: https://webrevs.openjdk.org/?repo=jmc&pr=611&range=00
  Issue: https://bugs.openjdk.org/browse/JMC-7539
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jmc/pull/611.diff
  Fetch: git fetch https://git.openjdk.org/jmc.git pull/611/head:pull/611

PR: https://git.openjdk.org/jmc/pull/611