Fix Linux plugin template build visibility (#58069)

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.
https://dart.googlesource.com/external/github.com/flutter/flutter/+/27e652c8825b877867784d135de9a70bcbbab157
1 file changed
tree: f0a813f1aa08261b61f78f5c148b8a5c02dcfc0c
  1. commits.json