bpf: Test bitmap open (duplicates GTS)

This test opens and closes the map, this makes
sure the map exists and can be opened.

Test: atest libbpf_android_test
Bug: 379821131
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Iada96f1ec0961f61d0710cb5ba00c8a86b0aedca
diff --git a/bpf/headers/BpfMapTest.cpp b/bpf/headers/BpfMapTest.cpp
index 862114d..33b88fa 100644
--- a/bpf/headers/BpfMapTest.cpp
+++ b/bpf/headers/BpfMapTest.cpp
@@ -250,5 +250,10 @@
     expectMapEmpty(testMap);
 }
 
+TEST_F(BpfMapTest, testGTSbitmapTestOpen) {
+    BpfMap<int, uint64_t> bitmap;
+    ASSERT_RESULT_OK(bitmap.init("/sys/fs/bpf/tethering/map_test_bitmap"));
+}
+
 }  // namespace bpf
 }  // namespace android