Use gtest_prod_headers.

Bug: http://b/185916167
Test: treehugger
Change-Id: I3407052df4f12b01acc4a75c6bd0759f7a4b2c4c
diff --git a/tests/Android.bp b/tests/Android.bp
index 0559dc3..5ef4d58 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -148,9 +148,11 @@
         "libupdater_core",
         "libupdate_verifier",
 
-        "libgtest_prod",
         "libprotobuf-cpp-lite",
     ],
+    header_libs: [
+        "libgtest_prod_headers",
+    ],
 
     data: [
         "testdata/*",