RFR: 8281745: Create a regression test for JDK-4514331

[Manukumar V S]

Create a regression test for JDK-4514331.
It checks whether pressing 'Tab' key always shift focus to next component, even though the current focus is in JTextArea and some text is already selected.

Testing:
I have verified this test with JDK 1.3.1 and JDK 1.4.1 .
The issue is reproducible with JDK 1.3.1 and the test failed there, where the bug was originally reported and the test passed in JDK 1.4.1 where the issue was fixed.
I have tested it in Linux, Mac and Windows platforms and it passed everywhere.

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Commit messages:
 - Create a regression test for JDK-4514331

Changes: https://git.openjdk.java.net/jdk/pull/7469/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7469&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8281745
  Stats: 134 lines in 1 file changed: 134 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7469.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7469/head:pull/7469

PR: https://git.openjdk.java.net/jdk/pull/7469