FileChooser Open/Approve button size is shown incorrectly when no Approve button text is set in `CUSTOM_DIALOG` type. Reason being that no default Approve Button text is returned during Dialog Type Property change. Since `null` is returned as Button string the Button size is incorrectly shown. The fix here addresses the issue by adding a default Approve Button Text when no text is set explicitly in case of `CUSTOM_DIALOG` type. Automated test is attached which has been tested with multiple test runs.
------------- Commit messages: - fix + Automated Test Changes: https://git.openjdk.org/jdk/pull/11901/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11901&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8299522 Stats: 150 lines in 3 files changed: 150 ins; 0 del; 0 mod Patch: https://git.openjdk.org/jdk/pull/11901.diff Fetch: git fetch https://git.openjdk.org/jdk pull/11901/head:pull/11901 PR: https://git.openjdk.org/jdk/pull/11901
