8329705: Add missing Application thread checks to platform specific a11y methods
------------- Commit messages: - Backport 0eb4d7196099d817cc6467985b882242845bdd2e Changes: https://git.openjdk.org/jfx21u/pull/61/files Webrev: https://webrevs.openjdk.org/?repo=jfx21u&pr=61&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8329705 Stats: 299 lines in 4 files changed: 299 ins; 0 del; 0 mod Patch: https://git.openjdk.org/jfx21u/pull/61.diff Fetch: git fetch https://git.openjdk.org/jfx21u.git pull/61/head:pull/61 PR: https://git.openjdk.org/jfx21u/pull/61
