netd_integration_test:BinderTest#GetFwmarkForNetwork - save/restore default network

Otherwise network connectivity after the test is run ceases.

Tested: via atest
Bug: 157114644
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I3e1dc027670644c1b4f0b2aa35a543c398b103be
Merged-In: I3e1dc027670644c1b4f0b2aa35a543c398b103be
diff --git a/tests/binder_test.cpp b/tests/binder_test.cpp
index 12d5cfb..f4da09a 100644
--- a/tests/binder_test.cpp
+++ b/tests/binder_test.cpp
@@ -3475,6 +3475,9 @@
 }  // namespace
 
 TEST_F(BinderTest, GetFwmarkForNetwork) {
+    // Save current default network.
+    ASSERT_TRUE(mNetd->networkGetDefault(&mStoredDefaultNetwork).isOk());
+
     in6_addr v6Addr = {
             {// 2001:db8:cafe::8888
              .u6_addr8 = {0x20, 0x01, 0x0d, 0xb8, 0xca, 0xfe, 0, 0, 0, 0, 0, 0, 0, 0, 0x88, 0x88}}};