ephemeral_app: restore /dev/ashmem open permissions

ephemeral_app domain doesn't distinguish between apps that target Q vs
ones target pre-Q. Restore ashmem permissions for older apps.

Bug: 130054503
Test: start com.nextlatam.augmentedfaces instant app
Change-Id: I490323cce96d69e561fc808426a9dfba2aeac30f
diff --git a/private/app_neverallows.te b/private/app_neverallows.te
index 17f4111..fcdd653 100644
--- a/private/app_neverallows.te
+++ b/private/app_neverallows.te
@@ -339,6 +339,7 @@
 # They must use ASharedMemory NDK API instead.
 neverallow {
   all_untrusted_apps
+  -ephemeral_app
   -untrusted_app_25
   -untrusted_app_27
 } ashmem_device:chr_file open;