Fix bug 4807086 - Options menu panel too narrow in landscape

Now that landscape on phones uses the config_prefDialogWidth setting
to restrict the default size of dialog windows, the options menu panel
was affected.

Restrict the ratcheting preferred width feature based on the width
LayoutParam only, and respect the LayoutParams width provided by panel
windows.

Change-Id: Idc62f41910f6f22dc50cab978c5642bb0a8dbdaf