Update the ibus config file

.config/mozc/ibus_config.textproto

@@ -1,5 +1,31 @@
+# `ibus write-cache; ibus restart` might be necessary to apply changes.
 engines {
   name : "mozc-jp"
   longname : "Mozc"
   layout : "default"
+  layout_variant : ""
+  layout_option : ""
+  rank : 80
+  symbol : "あ"
 }
+engines {
+  name : "mozc-on"
+  longname : "Mozc:あ"
+  layout : "default"
+  layout_variant : ""
+  layout_option : ""
+  rank : 99
+  symbol : "あ"
+  composition_mode : HIRAGANA
+}
+engines {
+  name : "mozc-off"
+  longname : "Mozc:A_"
+  layout : "default"
+  layout_variant : ""
+  layout_option : ""
+  rank : 99
+  symbol : "A"
+  composition_mode : DIRECT
+}
+active_on_launch: False