gn2bp: add device_supported property

Test: //components/cronet/android:cronet
Change-Id: Ic7b7eb8544e0b50bc05da44b15ce18e371724d3d
diff --git a/tools/gn2bp/gen_android_bp b/tools/gn2bp/gen_android_bp
index eb44f72..32ac640 100755
--- a/tools/gn2bp/gen_android_bp
+++ b/tools/gn2bp/gen_android_bp
@@ -347,6 +347,7 @@
     self.tools = set()
     self.cmd = None
     self.host_supported = False
+    self.device_supported = True
     self.vendor_available = False
     self.init_rc = set()
     self.out = set()
@@ -400,6 +401,8 @@
     self._output_field(output, 'cmd', sort=False)
     if self.host_supported:
       self._output_field(output, 'host_supported')
+    if not self.device_supported:
+      self._output_field(output, 'device_supported')
     if self.vendor_available:
       self._output_field(output, 'vendor_available')
     self._output_field(output, 'init_rc')