RFR: 8342270: Test sun/security/pkcs11/Provider/RequiredMechCheck.java needs write access to src tree

[Fernando Guallini]

The test sun/security/pkcs11/Provider/RequiredMechCheck.java extends sun/security/pkcs11/PKCS11Test.java, which sets up a PKCS11Provider configured with NSS config files located in the source tree directory (sun/security/pkcs11/nss) for the dependent tests to run properly. This test currently fails if that **pkcs11/nss** directory is made read-only because these config files are updated during the test execution. Files located in the source tree should not be modified when running tests. 
This PR updates the PKCS11Test to copy the NSS config files to the Jtreg scratch directory and configures the provider to use those files instead.

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Commit messages:
 - Merge branch 'master' into 8342270
 - renamed copyNssFiles to copyFiles
 - copy nss files to working dir

Changes: https://git.openjdk.org/jdk/pull/21665/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21665&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8342270
  Stats: 30 lines in 1 file changed: 28 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/21665.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21665/head:pull/21665

PR: https://git.openjdk.org/jdk/pull/21665