gn2bp: Make ldflags target specific

Bug: 265913942
Test: ./update_results.sh
Change-Id: Ia7184e9b765240afa76ea2f15089e5ab00e6e560
diff --git a/tools/gn2bp/gen_android_bp b/tools/gn2bp/gen_android_bp
index d8bc116..461fb0a 100755
--- a/tools/gn2bp/gen_android_bp
+++ b/tools/gn2bp/gen_android_bp
@@ -296,6 +296,7 @@
     self.export_system_include_dirs = set()
     self.generated_headers = set()
     self.export_generated_headers = set()
+    self.ldflags = set()
 
   def to_string(self, output):
     nested_out = []
@@ -313,6 +314,7 @@
     self._output_field(nested_out, 'export_system_include_dirs')
     self._output_field(nested_out, 'generated_headers')
     self._output_field(nested_out, 'export_generated_headers')
+    self._output_field(nested_out, 'ldflags')
 
     if nested_out:
       output.append('    %s: {' % self.name)