seccomp-x86: allow sched_yield and gettid syscalls

Addresses:
media.extractor: libminijail: blocked syscall: sched_yield, gettid

Bug: None
Test: make USE_CLANG_PLATFORM_BUILD:=true SANITIZE_TARGET=address -j42
      media extractor complains no more.
Change-Id: I3d499b0400df10ede08801fe6b608e6003727734
diff --git a/services/mediaextractor/seccomp_policy/mediaextractor-x86.policy b/services/mediaextractor/seccomp_policy/mediaextractor-x86.policy
index 19016cd..2ce6cf8 100644
--- a/services/mediaextractor/seccomp_policy/mediaextractor-x86.policy
+++ b/services/mediaextractor/seccomp_policy/mediaextractor-x86.policy
@@ -51,3 +51,7 @@
 getdents64: 1
 pipe2: 1
 ppoll: 1
+
+# Required by AddressSanitizer
+gettid: 1
+sched_yield: 1