<Swing Dev> RFR: 8260291: The case instruction is not visible in dark mode [v2]

[Pankaj Bansal]

> Please review a trivial test only fix.
> 
> This is a GTKL&F specific manual test and create an instruction panel containing JTextArea. The JTextArea background color is hardcoded as white color, which is causing issues on dark mode in Ubuntu 20.04 and Ubuntu 20.10 as the text color is also white. The fix is to remove the hardcoded white color as the JTextArea background color should be set by L&F and should not be hardcoded in test.

Pankaj Bansal has updated the pull request incrementally with one additional commit since the last revision:

  Revert "Add bugID"
  
  This reverts commit a84b6098bee8122abd159209a1ff857db716f4b4.

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/2564/files
  - new: https://git.openjdk.java.net/jdk/pull/2564/files/a84b6098..8eec0dd4

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=2564&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=2564&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2564.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2564/head:pull/2564

PR: https://git.openjdk.java.net/jdk/pull/2564