Sendsend a distributed notification from the config app
whenever a change to the enabled keyboards occurs.
In response, the input method loads the list of
enabled keyboards and updates the Keyman menu.
response to the AccessCheck message comes to the
InstallationCheck object, but the InstallationContainer
should only know about the higher level event:
whether the installation needs repair
when creating the InstallationCheck, first ask
for the Accessibility permission from the input
method, and once the response is returned via
DistributedNotificiationCenter message, then do
the rest of the validation
added booleans to indicate input method exists and
matches the current version
made installationState optional
made accessibilityPermissionGranted optional
added comments
