Define the proper macro "GTEST_OS_LINUX_ANDROID" for native tests.

Bug 7050760

Change-Id: I05e69b741eaf628ab1d25dec12a953f9f2a3d9a2
diff --git a/core/native_test.mk b/core/native_test.mk
index 3253a5e..ebe5edf 100644
--- a/core/native_test.mk
+++ b/core/native_test.mk
@@ -3,7 +3,7 @@
 ## Common flags for native tests are added.
 ###########################################
 
-LOCAL_CFLAGS += -DGTEST_OS_LINUX -DGTEST_HAS_STD_STRING
+LOCAL_CFLAGS += -DGTEST_OS_LINUX_ANDROID -DGTEST_HAS_STD_STRING
 LOCAL_C_INCLUDES += bionic \
                     bionic/libstdc++/include \
                     external/gtest/include \