RFR: 8298057: (fs) Remove PollingWatchService.POLLING_INIT_DELAY [v2]

[Alan Bateman]

> PollingWatchService is an implementation of WatchService for platforms that don't have a native implementation. It works by polling the timestamps of files in the registered directories. When a WatchService is initially created, the first poll should be at the polling interval. The changes in JDK-8285956 were intended to reduce the polling interval to 2s but also changed the initial poll to 1s. This PR just restores that part of the change so the first poll after creation will be at the polling interval, which was how it was originally before that change.

Alan Bateman has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:

 - Update copyright header
 - Merge
 - Initial commit

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Changes:
  - all: https://git.openjdk.org/jdk/pull/11499/files
  - new: https://git.openjdk.org/jdk/pull/11499/files/f3db40de..446127da

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=11499&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11499&range=00-01

  Stats: 21393 lines in 532 files changed: 10397 ins; 6494 del; 4502 mod
  Patch: https://git.openjdk.org/jdk/pull/11499.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11499/head:pull/11499

PR: https://git.openjdk.org/jdk/pull/11499