RFR: 8249693: java/nio/channels/FileChannel/FileExtensionAndMap.java uses @ignore w/o bug id

[Matthew Donovan]

Added a check that source and destination volumes have enough space to run the test.

This test will no longer be ignored.

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

Commit messages:
 - dummy commit
 - fixed line breaks, use FileStore::equals
 - updated copyright year
 - 8249693 Enabling test with check for available disk space.

Changes: https://git.openjdk.org/jdk/pull/11028/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11028&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8249693
  Stats: 42 lines in 1 file changed: 36 ins; 1 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/11028.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11028/head:pull/11028

PR: https://git.openjdk.org/jdk/pull/11028