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/AndroidManifest.xml b/AndroidManifest.xml
index 31b2f84..5547624 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -224,6 +224,18 @@
                 android:process=":ui">
         </activity>
 
+        <activity android:name=".components.ChangeDefaultDialerDialog"
+                  android:label="@string/change_default_dialer_dialog_title"
+                  android:excludeFromRecents="true"
+                  android:theme="@*android:style/Theme.Material.Light.Dialog.Alert"
+                  android:priority="1000"
+                  android:process=":ui" >
+            <intent-filter>
+                <action android:name="android.telecom.action.CHANGE_DEFAULT_DIALER" />
+                <category android:name="android.intent.category.DEFAULT" />
+            </intent-filter>
+        </activity>
+
         <receiver android:name=".components.PrimaryCallReceiver"
                 android:exported="true"
                 android:permission="android.permission.MODIFY_PHONE_STATE"