JDK 9 RFR of JDK-8149922: Remove intermittent key from security tests

[Amy Lu]

sun/security/mscapi/ShortRSAKey1024.sh
sun/security/mscapi/SignUsingSHA2withRSA.sh
javax/net/ssl/SSLSession/SessionCacheSizeTests.java

For above tests, previous intermittent test failure issues are fixed, no 
open bug (no failure reported).

This patch is to remove @key intermittent from tests.

This patch also removed SessionCacheSizeTests.java from ProblemList.txt 
as related bug (JDK-8146387) is resolved.

bug:
https://bugs.openjdk.java.net/browse/JDK-8149922
https://bugs.openjdk.java.net/browse/JDK-8150047

webrev:
http://cr.openjdk.java.net/~amlu/8149922/webrev.00/

Thanks,
Amy