openharmony-preinit: /dev/ashmem needs to be rw for all users

A wrong permission mode causes ActsAppdatamagrJsTest ACTS test suite to 
fail because it fails to open /dev/ashmem due to a "Permission denied" error. 
Changing permission to /dev/ashmem: "chmod 666 /dev/ashmem" because 
it needs to be rw for all users.

Signed-off-by: Francesco Pham <francesco.pham@huawei.com>

recipes-openharmony/openharmony/files/openharmony-preinit

@@ -77,8 +77,9 @@ mkdir -p /usr/lib/dri
 
 chmod -R 777 /data
 
-# /dev/binder needs to be rw for all users
+# /dev/binder and /dev/ashmem need to be rw for all users
 chmod 666 /dev/binder
+chmod 666 /dev/ashmem
 
 # /dev/dri/card0 needs to be rw for all users
 if [ -c /dev/dri/card0 ]; then