Use __ANDROID__ instead of HAVE_ANDROID_OS.

Change-Id: I9967f3fd758c2a5b40be5b60ae72be7e2fb75136
diff --git a/libutils/SystemClock.cpp b/libutils/SystemClock.cpp
index 64204a8..1fca2b2 100644
--- a/libutils/SystemClock.cpp
+++ b/libutils/SystemClock.cpp
@@ -19,7 +19,7 @@
  * System clock functions.
  */
 
-#ifdef HAVE_ANDROID_OS
+#if defined(__ANDROID__)
 #include <linux/ioctl.h>
 #include <linux/rtc.h>
 #include <utils/Atomic.h>
@@ -107,7 +107,7 @@
  */
 int64_t elapsedRealtimeNano()
 {
-#ifdef HAVE_ANDROID_OS
+#if defined(__ANDROID__)
     struct timespec ts;
     int result;
     int64_t timestamp;