Fix some broken tests in frameworks-net with native dependencies

Exempt-From-Owner-Approval: Android.mk uses per-file permission to let
the build team modify it without dependeing on us. However because this
rule overrides the directory default owners, Android core networking is
not owner anymore. This exemption is necessary to let Android core
networking team fix their build file.

Test: All tests in runtest frameworks-net pass.
Change-Id: Ie0b8baa38ca39e92fbd698ebcead86dac0a67708
diff --git a/tests/net/Android.mk b/tests/net/Android.mk
index e4bf590..677585c 100644
--- a/tests/net/Android.mk
+++ b/tests/net/Android.mk
@@ -53,6 +53,7 @@
     libtinyxml2 \
     libvintf \
     libhwbinder \
+    libunwindstack \
     android.hidl.token@1.0
 
 LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk