RFR: 8373946: Synth ProgressBarUI implementation confuses background painting with border painting [v3]

[Prasanta Sadhukhan]

> [JDK-8224261](https://bugs.openjdk.org/browse/JDK-8224261) fix controls background painting by checking if border is painted or not. This is wrong as background should always be painted else background will not be painted if border is not there
> JProgressBar.setBorderPainted spec says " Some look and feels might not implement painted borders; they will ignore this property." so not painting border is ok but not painting background is an issue
> 
> The JDK-8224261 is hereby backed out

Prasanta Sadhukhan has updated the pull request incrementally with one additional commit since the last revision:

  AUtomate test

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/28885/files
  - new: https://git.openjdk.org/jdk/pull/28885/files/a85d579d..6d742afb

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=28885&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=28885&range=01-02

  Stats: 91 lines in 1 file changed: 37 ins; 19 del; 35 mod
  Patch: https://git.openjdk.org/jdk/pull/28885.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28885/head:pull/28885

PR: https://git.openjdk.org/jdk/pull/28885