Make sure cc_shared_library is guarded by flag

The --experimental_cc_shared_library used to block API methods
that were needed in the cc_shared_library implementation. However, these
methods have been made freely available to everyone so that people can start
migrating to the new API.

With that change, the cc_shared_library has become free to use unless we block
it with the method call added in this CL.

RELNOTES:none
PiperOrigin-RevId: 297127873
Change-Id: I103fe7724b9c4956a5bee8bed0f6d074a6e453f1
diff --git a/examples/experimental_cc_shared_library.bzl b/examples/experimental_cc_shared_library.bzl
index e660742..07ea515 100644
--- a/examples/experimental_cc_shared_library.bzl
+++ b/examples/experimental_cc_shared_library.bzl
@@ -227,6 +227,7 @@
     return True
 
 def _cc_shared_library_impl(ctx):
+    cc_common.check_experimental_cc_shared_library()
     cc_toolchain = find_cc_toolchain(ctx)
     feature_configuration = cc_common.configure_features(
         ctx = ctx,