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.

core/java/android/provider/Settings.java

@@ -2312,6 +2312,14 @@ public final class Settings {
          */
         public static final String ENABLED_INPUT_METHODS = "enabled_input_methods";
 
+        /**
+         * List of system input methods that are currently disabled.  This is a string
+         * containing the IDs of all disabled input methods, each ID separated
+         * by ':'.
+         * @hide
+         */
+        public static final String DISABLED_SYSTEM_INPUT_METHODS = "disabled_system_input_methods";
+
         /**
          * Host name and port for a user-selected proxy.
          */