Implement KeyboardLocale InputMethodSubtype extra key

The locale is specified by KeyboardLocale extra key in method.xml,
LatinIME will use the specified locale for keyboard layout.

Bug: 5238658
Change-Id: I8e6cb66c73a7ac1bf611d9910b42fa9cff38eba0
diff --git a/java/res/values/strings.xml b/java/res/values/strings.xml
index 247bdba..2a3d705 100644
--- a/java/res/values/strings.xml
+++ b/java/res/values/strings.xml
@@ -332,11 +332,11 @@
     <!-- Title of the item to change the keyboard theme [CHAR LIMIT=20]-->
     <string name="keyboard_layout">Keyboard theme</string>
 
-    <!-- Description for German QWERTY keyboard subtype [CHAR LIMIT=35] -->
+    <!-- Description for German QWERTY keyboard subtype [CHAR LIMIT=22] -->
     <string name="subtype_de_qwerty">German QWERTY</string>
-    <!-- Description for English (United Kingdom) keyboard subtype [CHAR LIMIT=35] -->
+    <!-- Description for English (United Kingdom) keyboard subtype [CHAR LIMIT=22] -->
     <string name="subtype_en_GB">English (UK)</string>
-    <!-- Description for English (United States) keyboard subtype [CHAR LIMIT=35] -->
+    <!-- Description for English (United States) keyboard subtype [CHAR LIMIT=22] -->
     <string name="subtype_en_US">English (US)</string>
 
     <!-- Title of an option for usability study mode -->