[jdk17u-dev] RFR: 8297489: Modify TextAreaTextEventTest.java as to verify the content change of TextComponent sends TextEvent

[Goetz Lindenmaier]

I backport this for parity with 17.0.7-oracle.

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

Commit messages:
 - Backport 7d20a60a983e459ea1c4e843fbde70fb796c6249

Changes: https://git.openjdk.org/jdk17u-dev/pull/1161/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=1161&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8297489
  Stats: 302 lines in 2 files changed: 161 ins; 141 del; 0 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/1161.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev pull/1161/head:pull/1161

PR: https://git.openjdk.org/jdk17u-dev/pull/1161