Adb root is supported in Microdroid on user builds

In Android, adb root is disabled at build-time by not compiling
sepolicies which allows adbd to run in the `su` domain.

However in Microdroid, adb root should be supported even on user builds
because fully-debuggable VMs can be started and adb root is expected
there. Note that adb root is still not supported in non-debuggable VMs
by not starting it at all.

This change removes `userdebug_or_end` conditions from the policies for
adb root. In addition, the `su` domain where adbd runs when rooted is
explicitly marked as a permissive domain allowed.

Bug: 259729287
Test: build a user variant, run fully debuggable microdroid VM. adb root
works there.
Test: run non-debuggable microdroid VM. adb shell (not even adb root)
doesn't work.

Change-Id: I8bb40b7472dcda6619a587e832e22d3cb290c6b9
diff --git a/microdroid/Android.bp b/microdroid/Android.bp
index d1dcff0..12bb8f7 100644
--- a/microdroid/Android.bp
+++ b/microdroid/Android.bp
@@ -241,6 +241,11 @@
         ":microdroid_vendor_sepolicy.cil",
     ],
     installable: false,
+
+    // b/259729287. In Microdroid, su is allowed to be in permissive mode.
+    // This is to support fully debuggable VMs on user builds. This is safe
+    // because we don't start adbd at all on non-debuggable VMs.
+    permissive_domains_on_user_builds: ["su"],
 }
 
 genrule {