Add Trunk Stable flags to Autofill

Bug: 297380045

Test: N/A; config
Change-Id: I05c3081f0a93d776039eb35ace42ab39ca9d9f69
diff --git a/services/autofill/features.aconfig b/services/autofill/features.aconfig
new file mode 100644
index 0000000..1e44de6
--- /dev/null
+++ b/services/autofill/features.aconfig
@@ -0,0 +1 @@
+package: "android.service.autofill"
\ No newline at end of file