Remove unnecessary references to libunwind.

Bug: 79209464

Test: Builds.
Change-Id: I0fa7cb3c472dbf1b83c5301281692ab7f992cb6b
diff --git a/libandroid_net_lowpan/tests/Android.mk b/libandroid_net_lowpan/tests/Android.mk
index 7339b32..c525ef7 100644
--- a/libandroid_net_lowpan/tests/Android.mk
+++ b/libandroid_net_lowpan/tests/Android.mk
@@ -63,7 +63,6 @@
     libnativehelper \
     libnetdaidl \
     libui \
-    libunwind \
     libutils \
     libvndksupport \
     libcrypto \