RFR: 8216507: StyleablePropertyFactory: example in class javadoc does not compile

Fri Dec 23 14:01:37 UTC 2022

In the javadoc example of `StyleablePropertyFactory` class, wrong parameter was used while initializing `StyleableProperty`. 

Assigned the `CssMetadData` object to `SELECTED` variable returned by `createBooleanCssMetaData` method called in anonymous inner-class class, which is then used while initializing `StyleableProperty`.

Added missing semicolon in the same example.

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Commit messages:
 - fix issue in javadoc example

Changes: https://git.openjdk.org/jfx/pull/983/files
 Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=983&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8216507
  Stats: 5 lines in 1 file changed: 2 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jfx/pull/983.diff
  Fetch: git fetch https://git.openjdk.org/jfx pull/983/head:pull/983

PR: https://git.openjdk.org/jfx/pull/983