Allow system server to access tmpfs files

* For some reasons CachedAppOptimizer is throwing these kinds of denials [1]
  it wont probably hurt to allow access to tmpfs files since system server
  already have access to app domain and zygote tmpfs

[1]
 avc:  denied  { write } for  comm="CachedAppOptimi" dev="tmpfs" ino=34884 scontext=u:r:system_server:s0 tcontext=u:object_r:tmpfs:s0 tclass=file permissive=0
 avc:  denied  { write } for  comm="CachedAppOptimi" dev="tmpfs" ino=16233 scontext=u:r:system_server:s0 tcontext=u:object_r:zygote_tmpfs:s0 tclass=file permissive=0

Signed-off-by: minaripenguin <[email protected]>
Signed-off-by: Pranav Temkar <[email protected]>
Change-Id: I9207deadabb3bb4dc75be5215e32719a4346d1ca

private/system_server.te

@@ -22,7 +22,8 @@ type_transition system_server system_data_file:sock_file system_ndebug_socket "n
 # Create a socket for connections from zygotes.
 type_transition system_server system_data_file:sock_file system_unsolzygote_socket "unsolzygotesocket";
 
-allow system_server zygote_tmpfs:file { map read };
+allow system_server tmpfs:file { map read write };
+allow system_server zygote_tmpfs:file { map read write };
 allow system_server appdomain_tmpfs:file { getattr map read write };
 
 # For Incremental Service to check if incfs is available