Add and use constants for the Android API levels.

Test: bionic tests still pass
Change-Id: If1b619cfc9db1d3f5d91f14f2ace71058dca0c4a
diff --git a/libc/include/android/legacy_fenv_inlines_mips.h b/libc/include/android/legacy_fenv_inlines_mips.h
index ead697c..10b93c0 100644
--- a/libc/include/android/legacy_fenv_inlines_mips.h
+++ b/libc/include/android/legacy_fenv_inlines_mips.h
@@ -31,7 +31,7 @@
 
 #include <fenv.h>
 
-#if __ANDROID_API__ < 21 && (defined(__mips__) && !defined(__LP64__))
+#if __ANDROID_API__ < __ANDROID_API_L__ && (defined(__mips__) && !defined(__LP64__))
 
 __BEGIN_DECLS
 
@@ -163,6 +163,6 @@
 
 __END_DECLS
 
-#endif /* __ANDROID_API__ < 21 && (defined(__mips__) && !defined(__LP64__)) */
+#endif /* __ANDROID_API__ < __ANDROID_API_L__ && (defined(__mips__) && !defined(__LP64__)) */
 
 #endif /* ANDROID_LEGACY_FENV_INLINES_MIPS_H */