disablePrebuilt: also clear sanitizer-dependent Srcs

The new libc++ prebuilt has HWASan and non-HWASan variants for arm64.

Bug: 175635923
Test: checkout use-prebuilt-libcxx topic, build libc++demangle, verify
  that libc++demangle-install is not a valid build target

Change-Id: I34385c48aa7ad1401e2547d65d30a14fa342e304
diff --git a/cc/prebuilt.go b/cc/prebuilt.go
index 8f4b7df..cbb5d58 100644
--- a/cc/prebuilt.go
+++ b/cc/prebuilt.go
@@ -260,6 +260,9 @@
 
 func (p *prebuiltLibraryLinker) disablePrebuilt() {
 	p.properties.Srcs = nil
+	p.properties.Sanitized.None.Srcs = nil
+	p.properties.Sanitized.Address.Srcs = nil
+	p.properties.Sanitized.Hwaddress.Srcs = nil
 }
 
 // Implements versionedInterface