Add activity to handle default dialer requests

* ChangeDefaultDialerDialog provides the UI that can be used by
apps to request that the user select their package as the default
dialer.

* Add various manifest entries, strings etc for use in the UI

* Exercise TelecomManager.ACTION_CHANGE_DEFAULT_DIALER in
TestDialerActivity

Bug: 20304411

Change-Id: Ibc6678c44290f5c9aa00c294b55db74c2c6e09eb
diff --git a/res/values/strings.xml b/res/values/strings.xml
index b09cdce..ce010da 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -94,6 +94,15 @@
     <!-- Button label on the "Missing voicemail number" dialog -->
     <string name="add_vm_number_str">Add number</string>
 
+    <!-- Title of dialog used to comfirm whether the user intends to change the default dialer
+            application [CHAR LIMIT=55]-->
+    <string name="change_default_dialer_dialog_title">Change default Dialer app?</string>
+    <!-- Text in dialog used to confirm whether or not the user intends to change the default dialer, if a different default dialer has been previously set. -->
+    <string name="change_default_dialer_with_previous_app_set_text">Use <xliff:g id="new_app">%1$s</xliff:g> instead of <xliff:g id="current_app">%2$s</xliff:g> as your default dialer app?</string>
+    <!-- Text in dialog used to confirm whether or not the user intends to change the default dialer, if a different default dialer has not been previously set. -->
+    <string name="change_default_dialer_no_previous_app_set_text">Use <xliff:g id="new_app">%s</xliff:g> as your default dialer app?</string>
+
+
     <!-- DO NOT TRANSLATE. Label for test Subscription 0. -->
     <string name="test_account_0_label">Q Mobile</string>
     <!-- DO NOT TRANSLATE. Label for test Subscription 1. -->