[Event Engine] Add event engine core tests to iOS pull request process (#33084)

<!--

If you know who should review your pull request, please assign it to
that
person, otherwise the pull request would get assigned randomly.

If your pull request is for a specific language, please add the
appropriate
lang label.

-->

---------

Co-authored-by: Yash Tibrewal <yashkt@google.com>
Co-authored-by: Stanley Cheung <stanleycheung@google.com>
Co-authored-by: AJ Heller <hork@google.com>
Co-authored-by: Yijie Ma <yijiem.main@gmail.com>
Co-authored-by: apolcyn <apolcyn@google.com>
Co-authored-by: Jan Tattermusch <jtattermusch@google.com>

tools/internal_ci/macos/grpc_run_bazel_cpp_ios_tests.sh

@@ -42,7 +42,7 @@ BAZEL_REMOTE_CACHE_ARGS=(
 
 # only select ObjC test from the following subdirs
 # TODO(jtattermusch): start running selected tests from //test/core too.
-test_pattern="//test/cpp/end2end/... + //test/cpp/server/... + //test/cpp/client/... + //test/cpp/common/... + //test/cpp/codegen/... + //test/cpp/util/... + //test/cpp/grpclb/... + //test/cpp/test/..."
+test_pattern="//test/cpp/end2end/... + //test/cpp/server/... + //test/cpp/client/... + //test/cpp/common/... + //test/cpp/codegen/... + //test/cpp/util/... + //test/cpp/grpclb/... + //test/cpp/test/... + //test/core/event_engine/..."
 
 # iOS tests are marked as "manual" to prevent them from running by default. To run them, we need to use "bazel query" to list them first.
 ios_tests=$(tools/bazel query "kind(ios_unit_test, tests($test_pattern))" | grep '^//')