sepolicy: rework perfetto producer/profiler rules for "user" builds

This patch:
* allows for heap and perf profiling of all processes on the system
  (minus undumpable and otherwise incompatible domains). For apps, the
  rest of the platform will still perform checks based on
  profileable/debuggable manifest flags. For native processes, the
  profilers will check that the process runs as an allowlisted UID.
* allows for all apps (=appdomain) to act as perfetto tracing data
  writers (=perfetto_producer) for the ART java heap graph plugin
  (perfetto_hprof).
* allows for system_server to act a perfetto_producer for java heap
  graphs.

Bug: 247858731
Change-Id: I792ec1812d94b4fa9a8688ed74f2f62f6a7f33a6
diff --git a/private/crash_dump.te b/private/crash_dump.te
index 31f0128..bc6020e 100644
--- a/private/crash_dump.te
+++ b/private/crash_dump.te
@@ -30,13 +30,16 @@
   }:process { ptrace signal sigchld sigstop sigkill };
 ')
 
+# Read ART APEX data directory
+allow crash_dump apex_art_data_file:dir { getattr search };
+allow crash_dump apex_art_data_file:file r_file_perms;
+
 ###
 ### neverallow assertions
 ###
 
-# ptrace neverallow assertions are spread throughout the other policy
-# files, so we avoid adding redundant assertions here
-
+# sigchld not explicitly forbidden since it's part of the
+# domain-transition-on-exec macros, and is by itself not sensitive
 neverallow crash_dump {
   apexd
   userdebug_or_eng(`-apexd')
@@ -54,11 +57,7 @@
   vendor_init
   vold
   userdebug_or_eng(`-vold')
-}:process { signal sigstop sigkill };
+}:process { ptrace signal sigstop sigkill };
 
 neverallow crash_dump self:process ptrace;
 neverallow crash_dump gpu_device:chr_file *;
-
-# Read ART APEX data directory
-allow crash_dump apex_art_data_file:dir { getattr search };
-allow crash_dump apex_art_data_file:file r_file_perms;