Don't convert libc_dns using the cc_library_static bp2build converter.

Test: Manually ran bp2build-incremental presubmit in a new AOSP checkout.
Change-Id: I063f6f244c34c4456af77fb25579f95d724e8893
diff --git a/android/bazel.go b/android/bazel.go
index 9a14e70..c43ab6d 100644
--- a/android/bazel.go
+++ b/android/bazel.go
@@ -169,6 +169,7 @@
 		"liblinker_malloc":              true,
 		"liblinker_debuggerd_stub":      true,
 		"libbionic_tests_headers_posix": true,
+		"libc_dns":                      true,
 	}
 )