Share isolated properties across islolated apps

Introduce isolated_app_all typeattribute to share policies between
isolated_app and future similar apps that wish to be enforced with
isolation properties.

Bug: 255597123
Test: m && presubmit
Change-Id: I0d53816f71e7d7a91cc379bcba796ba65a197c89
diff --git a/private/app_neverallows.te b/private/app_neverallows.te
index 0579740..702879d 100644
--- a/private/app_neverallows.te
+++ b/private/app_neverallows.te
@@ -5,6 +5,7 @@
 define(`all_untrusted_apps',`{
   ephemeral_app
   isolated_app
+  isolated_app_all
   mediaprovider
   mediaprovider_app
   untrusted_app