Fix 2242164 Soft keyboard keeps getting enabled even if I disable it

On keyboardful devices, it is possible to disable the system soft input
method. Something changed in eclair that caused the ime to be re-enabled
on every package manager update (packages added/deleted).

Now keep track of disabled system imes in the settings db and search
in that list before enabling a system IME on package changes.

Every time the user goes to settings to enable/disable imes, the list
is re-created.

Any new system IMEs that may be added via an OTA will get enabled if
they have a different package name.