switch to official protobuf podspec (#27830)

src/cpp/Protobuf-C++.podspec

@@ -1,43 +0,0 @@
-Pod::Spec.new do |s|
-  s.name     = 'Protobuf-C++'
-  s.version  = '3.18.1'
-  s.summary  = 'Protocol Buffers v3 runtime library for C++.'
-  s.homepage = 'https://github.com/protocolbuffers/protobuf'
-  s.license  = '3-Clause BSD License'
-  s.authors  = { 'The Protocol Buffers contributors' => 'protobuf@googlegroups.com' }
-  s.cocoapods_version = '>= 1.0'
-
-  s.source = { :git => 'https://github.com/protocolbuffers/protobuf.git',
-               :tag => "v#{s.version}" }
-
-  s.source_files = 'src/google/protobuf/*.{h,cc,inc}',
-                   'src/google/protobuf/stubs/*.{h,cc}',
-                   'src/google/protobuf/io/*.{h,cc}',
-                   'src/google/protobuf/util/*.{h,cc}',
-                   'src/google/protobuf/util/internal/*.{h,cc}'
-
-  # Excluding all the tests in the directories above
-  s.exclude_files = 'src/google/**/*_test.{h,cc,inc}',
-                    'src/google/**/*_unittest.{h,cc}',
-                    'src/google/protobuf/test_util*.{h,cc}',
-                    'src/google/protobuf/map_lite_test_util.{h,cc}',
-                    'src/google/protobuf/map_test_util*.{h,cc,inc}',
-                    'src/google/protobuf/reflection_tester.{h,cc}'
-
-  s.header_mappings_dir = 'src'
-
-  s.ios.deployment_target = '9.0'
-  s.osx.deployment_target = '10.10'
-  s.tvos.deployment_target = '9.0'
-  s.watchos.deployment_target = '2.0'
-
-  s.pod_target_xcconfig = {
-    # Do not let src/google/protobuf/stubs/time.h override system API
-    'USE_HEADERMAP' => 'NO',
-    'ALWAYS_SEARCH_USER_PATHS' => 'NO',
-
-    # Configure tool is not being used for Xcode. When building, assume pthread is supported.
-    'GCC_PREPROCESSOR_DEFINITIONS' => '"$(inherited)" "HAVE_PTHREAD=1"',
-  }
-
-end

test/cpp/ios/Podfile

@@ -12,7 +12,7 @@ target 'CronetTests' do
 
   pod '!ProtoCompiler',            :path => "#{GRPC_LOCAL_SRC}/src/objective-c"
   pod '!ProtoCompiler-gRPCCppPlugin', :path => "#{GRPC_LOCAL_SRC}/src/objective-c"
-  pod 'Protobuf-C++', :podspec => "#{GRPC_LOCAL_SRC}/src/cpp", :inhibit_warnings => true
+  pod 'Protobuf-C++', :podspec => "#{GRPC_LOCAL_SRC}/third_party/protobuf", :inhibit_warnings => true
 
   pod 'BoringSSL-GRPC',       :podspec => "#{GRPC_LOCAL_SRC}/src/objective-c", :inhibit_warnings => true