Use libclang-cpp.so for cxx_extractor

Bug: http://b/150809112

This is a new upstream library that exports both the clang and LLVM C++
symbols and can replace libLLVM and (android-toolchain-only)
libclang_cxx.so.

Test: Build and run cxx_extractor
Change-Id: Icbedba95d6d39152574cdd235131d313467e6827
diff --git a/Android.bp b/Android.bp
index 200ab79..1c1cd10 100644
--- a/Android.bp
+++ b/Android.bp
@@ -164,8 +164,7 @@
     ],
     shared_libs: [
         "libbase",
-        "libLLVM_host",
-        "libclang_cxx_host",
+        "libclang-cpp_host",
         "libziparchive",
     ],
     header_libs: [