Use gtest_prod_headers.

Bug: http://b/185916167
Test: treehugger
Change-Id: I3407052df4f12b01acc4a75c6bd0759f7a4b2c4c
diff --git a/updater/Android.mk b/updater/Android.mk
index ddd4d86..bb1c07d 100644
--- a/updater/Android.mk
+++ b/updater/Android.mk
@@ -34,7 +34,6 @@
     libfec_rs \
     libavb \
     libverity_tree \
-    libgtest_prod \
     liblog \
     liblp \
     libselinux \
@@ -96,6 +95,8 @@
     libtune2fs \
     $(tune2fs_static_libraries)
 
+LOCAL_HEADER_LIBRARIES := libgtest_prod_headers
+
 LOCAL_MODULE_CLASS := EXECUTABLES
 inc := $(call local-generated-sources-dir)/register.inc