RFR(XXS) : 8149700 : Remove jdk_svc test group from tier * groups

[Igor Ignatyev]

http://cr.openjdk.java.net/~iignatyev/8149700/webrev.00/
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> 2 lines changed: 0 ins; 1 del; 1 mod;

Hi all,

could you please review the tiny patch which removes jdk_svc test group from tier2 test group? Many of svc tests fail intermittently due to different reasons, that prevents us from having all-pass runs in tier 2+.

JBS: https://bugs.openjdk.java.net/browse/JDK-8149700

Thanks,
— Igor