Fix Objective-C test pods for Cronet tests
diff --git a/gRPC-Core.podspec b/gRPC-Core.podspec
index 10e9d00..50fc9e9 100644
--- a/gRPC-Core.podspec
+++ b/gRPC-Core.podspec
@@ -770,12 +770,16 @@
     ss.source_files = 'include/grpc/grpc_cronet.h'
   end
 
+  s.subspec 'Cronet-Implement' do |ss|
+    ss.header_mappings_dir = '.'
+    ss.source_files = 'src/core/ext/transport/cronet/client/secure/cronet_channel_create.c',
+                      'src/core/ext/transport/cronet/transport/cronet_transport.c'
+  end
+
   s.subspec 'Cronet-Tests' do |ss|
     ss.header_mappings_dir = '.'
 
-    ss.source_files = 'src/core/ext/transport/cronet/client/secure/cronet_channel_create.c',
-                      'src/core/ext/transport/cronet/transport/cronet_transport.c',
-                      'test/core/end2end/cq_verifier.{c,h}',
+    ss.source_files = 'test/core/end2end/cq_verifier.{c,h}',
                       'test/core/end2end/end2end_tests.{c,h}',
                       'test/core/end2end/tests/*.{c,h}',
                       'test/core/end2end/data/*.{c,h}',