gn2bp: Use ldflags to specify linker script

Follow workaround in aosp/2389777

Test: ./update_results.sh, TH in aosp/2398772
Change-Id: I43166004a20ca73c3375618232b349e724cfd211
diff --git a/tools/gn2bp/Android.bp.swp b/tools/gn2bp/Android.bp.swp
index 4d4a0b2..e013b1e 100644
--- a/tools/gn2bp/Android.bp.swp
+++ b/tools/gn2bp/Android.bp.swp
@@ -2469,8 +2469,8 @@
         "third_party/protobuf/src/",
     ],
     cpp_std: "c++17",
-    linker_scripts: [
-        "base/android/library_loader/anchor_functions.lds",
+    ldflags: [
+        "-Wl,--script,external/cronet/base/android/library_loader/anchor_functions.lds",
     ],
     stem: "libcronet.108.0.5359.128",
     target: {