Refactoring vCard importer/exporter.

Rename ImportVCardService to VCardService and make it responsible for all the import/export works.
The service itself asks ImportProcessor/ExportProcessor to handle each request.
This implementation seems much more easier to be tested than the previous ones.

Bug: 2733143

Change-Id: I7b7d391e4ba294f74c8bbcdfb053368b61b498ca
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 48ff0da..24dfe86 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -535,13 +535,13 @@
         <activity android:name=".vcard.SelectAccountActivity"
             android:theme="@style/BackgroundOnly" />
 
-        <service
-            android:name=".vcard.ImportVCardService"
-            android:exported="false" />
-
         <activity android:name=".vcard.ExportVCardActivity"
             android:theme="@style/BackgroundOnly" />
 
+        <service
+            android:name=".vcard.VCardService"
+            android:exported="false" />
+
         <!-- Pinned header list demo -->
         <activity android:name=".widget.PinnedHeaderListDemoActivity">
             <intent-filter>