Remove 'google-build-namespaces' errors.

Some headers are using unnamed namespaces, which is an error with the
above compiler option.

Test: Compiles
Bug: b/142476146
Change-Id: Ia419571ef20520a7aa0ffb5fba25a184ca0efd06
diff --git a/.clang-tidy b/.clang-tidy
index d217441..320d9bf 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -1,6 +1,6 @@
 ---
 Checks: 'modernize-use-nullptr,google-build-namespaces,google-build-explicit-make-pair,readability-function-size,performance-*,bugprone-*'
-WarningsAsErrors: 'modernize-use-nullptr,google-build-namespaces,google-build-explicit-make-pair,readability-function-size,performance-*,bugprone-*'
+WarningsAsErrors: 'modernize-use-nullptr,google-build-explicit-make-pair,readability-function-size,performance-*,bugprone-*'
 CheckOptions:
   - key:    readability-function-size.StatementThreshold
     value:  '450'