RFR: 8251267: CDS tests should use CDSTestUtils.getOutputDir instead of System.getProperty("user.dir")

[Calvin Cheung]

Replacing
    `String s = System.getProperty("user.dir");` 
with
    `String s = CDSTestUtils.getOutputDir(); `

Replacing
    `File dir = new File(System.getProperty("user.dir"));`
with
    `File dir = CDSTestUtils.getOutputDirAsFile();`

Passed tier1, hs-tiers 2/3/4 tests.

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

Commit messages:
 - 8251267: CDS tests should use CDSTestUtils.getOutputDir instead of System.getProperty("user.dir")

Changes: https://git.openjdk.java.net/jdk/pull/1700/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1700&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8251267
  Stats: 59 lines in 24 files changed: 24 ins; 0 del; 35 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1700.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1700/head:pull/1700

PR: https://git.openjdk.java.net/jdk/pull/1700