[CLATJ#28] ClatCoordinator: spawn clatd with flag POSIX_SPAWN_CLOEXEC_DEFAULT am: 88ca23c28f

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/1956072

Change-Id: I851a68785049b5b2baa2b93571c5c1f67a316468
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>