RFR: 8292280: Unused field 'keyListener' in BasicRadioButtonUI [v2]

[Andrey Turbanov]

> Field `keyListener` was added under [JDK-8033699](https://bugs.openjdk.org/browse/JDK-8033699). But then all its usages were removed in [JDK-8249548](https://bugs.openjdk.org/browse/JDK-8249548)

Andrey Turbanov has updated the pull request incrementally with one additional commit since the last revision:

  8292280: Unused field 'keyListener' in BasicRadioButtonUI
  
  reverted unrelated changes

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/9832/files
  - new: https://git.openjdk.org/jdk/pull/9832/files/f5957cd5..fa6deb66

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9832&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9832&range=00-01

  Stats: 2 lines in 1 file changed: 2 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/9832.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9832/head:pull/9832

PR: https://git.openjdk.org/jdk/pull/9832