init.te: allow writting to /proc/sys/vm/overcommit_memory

Since there is "write /proc/sys/vm/overcommit_memory 1" line in init.rc

Change-Id: I5899d2802e7fa56b438a06d4cadb4eb6827bfe16
Signed-off-by: Yongqin Liu <yongqin.liu@linaro.org>

init.te

@@ -324,6 +324,9 @@ allow init init:key { write search setattr };
 # Allow init to create /data/unencrypted
 allow init unencrypted_data_file:dir create_dir_perms;
 
+# Allow init to write to /proc/sys/vm/overcommit_memory
+allow init proc_overcommit_memory:file { write };
+
 unix_socket_connect(init, vold, vold)
 
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