AllowRestartableSequences: Add whole /proc

Adding `/proc/self/cpuset` is not really correct.

PiperOrigin-RevId: 899621984
Change-Id: Ifd012394b34c95e150dac3a1e45670a6f3ce2b15

Author: happyCoder92

sandboxed_api/sandbox2/policybuilder.cc

@@ -1128,14 +1128,12 @@ PolicyBuilder& PolicyBuilder::AllowRestartableSequences(
                                             });
     AllowPrctlSetVma();
 
-    AddFileIfNamespaced("/proc/cpuinfo");
-    AddFileIfNamespaced("/proc/stat");
+    AddDirectoryIfNamespaced("/proc");
     AddDirectoryIfNamespaced("/sys/devices/system/cpu");
   }
   if (cpu_fence_mode == kAllowSlowFences && !allowed_complex_.slow_fences) {
     AllowSyscall(__NR_sched_getaffinity);
     AllowSyscall(__NR_sched_setaffinity);
-    AddFileIfNamespaced("/proc/self/cpuset");
     allowed_complex_.slow_fences = true;
   } else if (cpu_fence_mode == kRequireFastFences) {
     allowed_complex_.fast_fences = true;