RFR: 8323554: The typos in Javadoc: "@return if "

[Sergey Bylokhov]

The docs for the boolean methods are updated from this style:

@return if the event has been consumed

to this one

@return {@code true} if the event has been consumed, otherwise
{@code false}

plus small cleanups here and there.

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Commit messages:
 - one more
 - one more typo
 - 8323554: The typos in Javadoc: "@return if "

Changes: https://git.openjdk.org/jdk/pull/17357/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17357&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8323554
  Stats: 123 lines in 14 files changed: 23 ins; 16 del; 84 mod
  Patch: https://git.openjdk.org/jdk/pull/17357.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17357/head:pull/17357

PR: https://git.openjdk.org/jdk/pull/17357