Lower visibility to package

Lower visibility to package

This is a private-class method, it is fair game to declare it as
package-private, as noone can observe it outside of the nest.

Remove the need for shenanigans and lower access to the sole
method.

Change-Id: I5d44202f28e21ce57666f607f5634191ff517f17
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>