mediacodec: Add a couple 32-bit permissions

We add permissions for 'readlink' and 'open' for 32-bit targets.
These are used when grabbing bug reports, at least on some
32-bit devices.

Test: Tried this change on a 32-bit device that was getting fatal
aborts when taking bugreports, and confirm we no longer get fatal
aborts.
Bug: 132807384

Change-Id: I526217e9201d2a709baa2a6d9f078244578d678d

services/mediacodec/seccomp_policy/mediaswcodec-arm.policy

@@ -42,6 +42,7 @@ exit: 1
 lseek: 1
 rt_sigprocmask: 1
 openat: 1
+open: 1
 fstat64: 1
 write: 1
 nanosleep: 1
@@ -49,6 +50,7 @@ setpriority: 1
 set_tid_address: 1
 getdents64: 1
 readlinkat: 1
+readlink: 1
 read: 1
 pread64: 1
 fstatfs64: 1