podfile cleanup (#28175)

all tests pass, merged

gRPC-Core.podspec

@@ -2359,8 +2359,7 @@ Pod::Spec.new do |s|
   s.prepare_command = <<-END_OF_COMMAND
     set -e
     find src/core -type f \\( -path '*.h' -or -path '*.cc' \\) -print0 | xargs -0 -L1 sed -E -i'.grpc_back' 's;#include <openssl/(.*)>;#if COCOAPODS==1\\\n  #include <openssl_grpc/\\1>\\\n#else\\\n  #include <openssl/\\1>\\\n#endif;g'
-    find src/core -type f \\( -path '*.h' -or -path '*.cc' -or -path '*.c' \\) -print0 | xargs -0 -L1 sed -E -i'.grpc_back' 's;#include <uv.h>;#if COCOAPODS==1\\\n  #include <uv/uv.h>\\\n#else\\\n  #include  <uv.h>\\\n#endif;g'
     find third_party/xxhash  -type f -name xxhash.h -print0 | xargs -0 -L1 sed -E -i'.grpc_back' 's;@param([^,]*),;@param\\1 ,;g'
-    find src/core/ third_party/xxhash/ third_party/uv/ -type f -name '*.grpc_back' -print0 | xargs -0 rm
+    find src/core/ third_party/xxhash/ -type f -name '*.grpc_back' -print0 | xargs -0 rm
   END_OF_COMMAND
 end

templates/gRPC-Core.podspec.template

@@ -243,8 +243,7 @@
     s.prepare_command = <<-END_OF_COMMAND
       set -e
       find src/core -type f \\( -path '*.h' -or -path '*.cc' \\) -print0 | xargs -0 -L1 sed -E -i'.grpc_back' 's;#include <openssl/(.*)>;#if COCOAPODS==1\\\n  #include <openssl_grpc/\\1>\\\n#else\\\n  #include <openssl/\\1>\\\n#endif;g'
-      find src/core -type f \\( -path '*.h' -or -path '*.cc' -or -path '*.c' \\) -print0 | xargs -0 -L1 sed -E -i'.grpc_back' 's;#include <uv.h>;#if COCOAPODS==1\\\n  #include <uv/uv.h>\\\n#else\\\n  #include  <uv.h>\\\n#endif;g'
       find third_party/xxhash  -type f -name xxhash.h -print0 | xargs -0 -L1 sed -E -i'.grpc_back' 's;@param([^,]*),;@param\\1 ,;g'
-      find src/core/ third_party/xxhash/ third_party/uv/ -type f -name '*.grpc_back' -print0 | xargs -0 rm
+      find src/core/ third_party/xxhash/ -type f -name '*.grpc_back' -print0 | xargs -0 rm
     END_OF_COMMAND
   end