add comment to sync Bazel clang-tidy rules

The Bazel rules now have a separate implementation of the logic to
add flags to clang-tidy. This should be kept up to date with the Soong
implementation.

Bug: 195029134
Change-Id: I61efda081bf1627d352887b13a70d1d53944d368

cc/tidy.go

@@ -68,6 +68,7 @@ func (tidy *tidyFeature) props() []interface{} {
 // Then, that old style usage will be obsolete and an error.
 const NoWarningsAsErrorsInTidyFlags = true
 
+// keep this up to date with https://cs.android.com/android/platform/superproject/+/master:build/bazel/rules/cc/clang_tidy.bzl
 func (tidy *tidyFeature) flags(ctx ModuleContext, flags Flags) Flags {
 	CheckBadTidyFlags(ctx, "tidy_flags", tidy.Properties.Tidy_flags)
 	CheckBadTidyChecks(ctx, "tidy_checks", tidy.Properties.Tidy_checks)