This reverts commit f77c669d.

In #55864 a race condition was described where a done event is received before we finish connecting. This cannot happen, since async functions begin synchronously and the flag isWaitingForVm is tripped immediately, keeping onDone from exiting.

The CMake plugin build wasn't setting visibility to hidden by default,
which meant that plugins exported everything by default. This would make
bad interactions between plugins much more likely; only the intended API
should be exported by the shared library.

When you run this, bash complains that `local` is only valid in functions. Gets rid of that extraneous warning.

Just adding some more details to the snippets README.md file about testing snippets.

Add code example for CustomScrollView on how to make it grow in two directions along its scroll axis (#57670)

* Have _warpToCurrentIndex() shortcut logic behave properly

* Add test

* Apply code review

* Fix typo (fromm -> from)