Members in PolicyControl can be accessed by multiple threads via the
public functions called by PhoneWindowManager. Most of the functions
are called with the window-manager-lock held, but reloadFromSetting()
is an exception.
In this patch, we acquire the window-manager-lock before calling
reloadFromSetting() to ensure accessing the members with the same
lock held.
Change-Id: I54ac5cab2a2d74c568fa96145f7a6741c6d99e36