Allow app to write to sdk_sandbox

Change-Id: I2e308ca9ce58e71ac9d7d9b0fa515bdf2f5dfa1f
Bug: b/229251344
Test: Manual
diff --git a/private/untrusted_app.te b/private/untrusted_app.te
index 62d458d..56e44db 100644
--- a/private/untrusted_app.te
+++ b/private/untrusted_app.te
@@ -14,3 +14,10 @@
 untrusted_app_domain(untrusted_app)
 net_domain(untrusted_app)
 bluetooth_domain(untrusted_app)
+
+# Allow webview to access fd shared by sdksandbox for experiments data
+# TODO(b/229249719): Will not be supported in Android U
+allow untrusted_app sdk_sandbox_data_file:fd use;
+allow untrusted_app sdk_sandbox_data_file:file write;
+
+neverallow untrusted_app sdk_sandbox_data_file:file { open create };
\ No newline at end of file