Fix leak in test_subscription_content_filter_options.cpp

[sloretz]

I was checking rcl under the Address Sanitizer and noticed a leak in this test. It's missing a delete on the subscription pointer. I used std::unique_ptr to fix it since the tests are C++.

103: ==25716==ERROR: LeakSanitizer: detected memory leaks
103: 
103: Direct leak of 16 byte(s) in 2 object(s) allocated from:
103:     #0 0x7f6a74ffd1c7 in operator new(unsigned long) ../../../../src/libsanitizer/asan/asan_new_delete.cpp:99
103:     #1 0x557a65297980 in TestSubscriptionContentFilterOptions::SetUp() (/home/sloretz/ws/ros2/build/rcl/test/test_subscription_content_filter_options+0x30980)
103:     #2 0x557a6531c97f in void testing::internal::HandleSehExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) /home/sloretz/ws/ros2/install/gtest_vendor/src/gtest_vendor/./src/gtest.cc:2433
103:     #3 0x557a6530c30d in void testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) /home/sloretz/ws/ros2/install/gtest_vendor/src/gtest_vendor/./src/gtest.cc:2469
103:     #4 0x557a652b33e6 in testing::Test::Run() /home/sloretz/ws/ros2/install/gtest_vendor/src/gtest_vendor/./src/gtest.cc:2503
103:     #5 0x557a652b497a in testing::TestInfo::Run() /home/sloretz/ws/ros2/install/gtest_vendor/src/gtest_vendor/./src/gtest.cc:2684
103:     #6 0x557a652b56b2 in testing::TestSuite::Run() /home/sloretz/ws/ros2/install/gtest_vendor/src/gtest_vendor/./src/gtest.cc:2816
103:     #7 0x557a652d2619 in testing::internal::UnitTestImpl::RunAllTests() /home/sloretz/ws/ros2/install/gtest_vendor/src/gtest_vendor/./src/gtest.cc:5338
103:     #8 0x557a6531fda5 in bool testing::internal::HandleSehExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) /home/sloretz/ws/ros2/install/gtest_vendor/src/gtest_vendor/./src/gtest.cc:2433
103:     #9 0x557a6530ee4e in bool testing::internal::HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) /home/sloretz/ws/ros2/install/gtest_vendor/src/gtest_vendor/./src/gtest.cc:2469
103:     #10 0x557a652cf0ad in testing::UnitTest::Run() /home/sloretz/ws/ros2/install/gtest_vendor/src/gtest_vendor/./src/gtest.cc:4925
103:     #11 0x557a6529f239 in RUN_ALL_TESTS() /home/sloretz/ws/ros2/install/gtest_vendor/src/gtest_vendor/include/gtest/gtest.h:2473
103:     #12 0x557a6529f102 in main /home/sloretz/ws/ros2/install/gtest_vendor/src/gtest_vendor/src/gtest_main.cc:45
103:     #13 0x7f6a72fced8f  (/lib/x86_64-linux-gnu/libc.so.6+0x29d8f)
103: 
103: SUMMARY: AddressSanitizer: 16 byte(s) leaked in 2 allocation(s).
103: -- run_test.py: return code 1
103: -- run_test.py: inject classname prefix into gtest result file '/home/sloretz/ws/ros2/build/rcl/test_results/rcl/test_subscription_content_filter_options.gtest.xml'
103: -- run_test.py: verify result file '/home/sloretz/ws/ros2/build/rcl/test_results/rcl/test_subscription_content_filter_options.gtest.xml'
1/1 Test #103: test_subscription_content_filter_options ...***Failed    0.68 sec

I also updated the names of the class member variables to match the ROS 2 style guide.

[sloretz]

CI (build: --packages-up-to rcl test: --packages-select rcl)

• Linux
• Linux-aarch64
• Windows

[fujitatomoya]

lgtm, thanks!