Allow system processes to use vfork

java.lang.ProcessBuilder is internally using vfork in the current
configuration (see UNIXProcess_md.c in libcore).

Test: On an x86 Chromebook, trigger dropbox error event (1. settings
      put global logcat_for_system_app_anr 50; 2. kill -19 `pidof
      com.android.settings'; touch Settings).  Saw seccomp error in
      logcat but only without this fix.
Test: fyi, not reproducible on walleye (arm64)
Bug: 74441404

Change-Id: I1f40ae0fe0607c5834ecbe040ed31c4c0e42131d
diff --git a/libc/SECCOMP_WHITELIST_COMMON.TXT b/libc/SECCOMP_WHITELIST_COMMON.TXT
index f4b033e..08a2c2b 100644
--- a/libc/SECCOMP_WHITELIST_COMMON.TXT
+++ b/libc/SECCOMP_WHITELIST_COMMON.TXT
@@ -39,6 +39,9 @@
 int	fstat64|fstat:fstat(int, struct stat*)	mips64
 int	_flush_cache:cacheflush(char* addr, const int nbytes, const int op)	mips64
 
+# vfork is used by java.lang.ProcessBuilder
+pid_t	vfork:vfork()	arm,x86,x86_64
+
 # Needed for performance tools
 int	perf_event_open:perf_event_open(struct perf_event_attr *attr, pid_t pid, int cpu, int group_fd, unsigned long flags)	all