clatd: only wait 15s for SIGTERM during shutdown am: 9c05f75eaa

Original change: https://android-review.googlesource.com/c/platform/external/android-clat/+/2535679

Change-Id: I7d6d96b6ba8617b8c1f1b96075091195214990bb
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>