header-checker: Fix unit test include directories

This commit fixes the built-in include directories for header-abi-dumper
unit test cases. Remove the reference to
`prebuilts/sdk/renderscript/clang-include` because we don't check out
`prebuilts/sdk` in `aosp-clang-tools` branch.

Test: PATH=out/soong/dist/bin:$PATH \
development/vndk/tools/header-checker/tests/test.py

Change-Id: Ieb24b0a53b719f4569149251efcdaa3722c0b88c

vndk/tools/header-checker/utils/utils.py

@@ -19,7 +19,7 @@ except KeyError:
 BUILTIN_HEADERS_DIR = (
     os.path.join(AOSP_DIR, 'bionic', 'libc', 'include'),
     os.path.join(AOSP_DIR, 'external', 'libcxx', 'include'),
-    os.path.join(AOSP_DIR, 'prebuilts', 'sdk', 'renderscript', 'clang-include'),
+    os.path.join(AOSP_DIR, 'prebuilts', 'clang-tools', 'linux-x86', 'clang-headers'),
 )
 
 EXPORTED_HEADERS_DIR = (