Explicitly declare dependencies on libbase macros.

These were being included transitively through libhidl.

Test: links
Bug: 37791060
Change-Id: I6cbe3a64b1ae078b4625c5e4b905be50e04f7a55
(cherry picked from commit 52868f226ec5e7bb02947c5647bc8b803c8bae83)
diff --git a/keystore/Android.mk b/keystore/Android.mk
index 8231bf1..f87675d 100644
--- a/keystore/Android.mk
+++ b/keystore/Android.mk
@@ -63,6 +63,7 @@
 	libhidltransport \
 	android.hardware.keymaster@3.0 \
 	android.system.wifi.keystore@1.0
+LOCAL_HEADER_LIBRARIES := libbase_headers
 LOCAL_MODULE := keystore
 LOCAL_MODULE_TAGS := optional
 LOCAL_INIT_RC := keystore.rc