Make libbacktrace buildable for native_bridge

Bug: http://b/153609531

Test: m -j64 libbacktrace.native_bridge

Change-Id: I2b8a881b4e952f3b68dbcaeb14f147a6d955b406
diff --git a/libutils/Android.bp b/libutils/Android.bp
index ea39d34..7392806 100644
--- a/libutils/Android.bp
+++ b/libutils/Android.bp
@@ -169,6 +169,8 @@
 cc_library {
     name: "libutilscallstack",
     defaults: ["libutils_defaults"],
+    // TODO(b/153609531): remove when no longer needed.
+    native_bridge_supported: true,
 
     srcs: [
         "CallStack.cpp",