Establish Objective C end-to-end core test with Cronet
diff --git a/gRPC-Core.podspec b/gRPC-Core.podspec
index 4811abf..0678f3b 100644
--- a/gRPC-Core.podspec
+++ b/gRPC-Core.podspec
@@ -101,6 +101,8 @@
'ALWAYS_SEARCH_USER_PATHS' => 'NO',
}
+ s.default_subspecs = 'Interface', 'Implementation'
+
# Like many other C libraries, gRPC-Core has its public headers under `include/<libname>/` and its
# sources and private headers in other directories outside `include/`. Cocoapods' linter doesn't
# allow any header to be listed outside the `header_mappings_dir` (even though doing so works in
