RFR: 8365577: Revert to OpenGL as the default JavaFX rendering pipeline for macOS

[Ambarish Rapte]

On macOS, the default rendering pipeline was temporarily set to Metal.
This change reverts it to es2, by simply reverting the commit fa2127cb3a3fc11238c5c8ce4cf0d15c4000f05c for [JDK-8365576](https://bugs.openjdk.org/browse/JDK-8365576): Temporarily make Metal the default JavaFX rendering pipeline for macOS

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Commit messages:
 - Revert "8365576: Temporarily make Metal the default JavaFX rendering pipeline for macOS"

Changes: https://git.openjdk.org/jfx/pull/1930/files
  Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1930&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8365577
  Stats: 3 lines in 1 file changed: 0 ins; 2 del; 1 mod
  Patch: https://git.openjdk.org/jfx/pull/1930.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1930/head:pull/1930

PR: https://git.openjdk.org/jfx/pull/1930