RFR: 8163498: Many long-running security libs tests

[Fernando Guallini]

The following tests have been split based on lower/higher key sizes in order to reduce individual execution time and run in parallel with jtreg
sun/security/provider/DSA/SupportedDSAParamGen.java
sun/security/provider/NSASuiteB/TestDSAGenParameterSpec.java
com/sun/crypto/provider/KeyAgreement/SupportedDHParamGens.java

sun/security/rsa/SignatureTest.java is now using a fake generator since its objective is to test signature not key generation itself. In addition, it was generating and verifying the same key twice, with same modulus and exponent. That redundancy is removed. This speeds up the execution from ~54s to ~25s on average

-------------

Commit messages:
 - rename tests
 - remove updated copyright year in new files
 - split long running files inot two
 - use fake key generator and remove not needed code

Changes: https://git.openjdk.java.net/jdk/pull/2381/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2381&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8163498
  Stats: 215 lines in 8 files changed: 192 ins; 11 del; 12 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2381.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2381/head:pull/2381

PR: https://git.openjdk.java.net/jdk/pull/2381