Don't export libutils_headers from libbase

libutils headers are only used by the implementation of libbase,
and should not be exported to everything that uses libbase headers.

Test: m -j
Change-Id: I76f248908f649e3a3c91cd3e84d629a0049939ef

base/Android.bp

@@ -26,9 +26,6 @@ cc_library_headers {
     host_supported: true,
     export_include_dirs: ["include"],
 
-    header_libs: ["libutils_headers"],
-    export_header_lib_headers: ["libutils_headers"],
-
     target: {
         linux_bionic: {
             enabled: true,
@@ -54,7 +51,10 @@ cc_library {
         "test_utils.cpp",
     ],
 
-    header_libs: ["libbase_headers"],
+    header_libs: [
+        "libbase_headers",
+        "libutils_headers",
+    ],
     export_header_lib_headers: ["libbase_headers"],
 
     cppflags: libbase_cppflags,