Add call accessibility activity.

This pulls accessibility settings (which are not SIM-dependent) from
CallFeaturesSettings to their own Activity.

+ Added Accessibility settings activity and fragment.
+ Moved logic from CallFeatureSettings to new activity.
+ Defined a new file for constants pertaining to settings.

Bug: 19372734
Change-Id: I12d03c6c97c4573641c075a856dcc68260a579b8
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 3ae121c..2a3f3bd 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -1261,6 +1261,11 @@
     <string name="sim_label_emergency_calls">Emergency calls</string>
     <string name="sim_description_emergency_calls">Emergency calling only</string>
     <string name="sim_description_default">SIM card, slot: <xliff:g id="slot_id">%s</xliff:g></string>
+
+    <!-- Title for activity to control accessibility settings such as TTY mode and hearing aid
+         compatability. [CHAR LIMIT=40] -->
+    <string name="accessibility_settings_activity_title">Accessibility</string>
+
     <!-- Configuration setting for world mode Format is <true;GID if any to be checked>-->
     <string translatable="false" name="config_world_mode"/>