Change AOSP Contacts (master-dev) version from 2.1 to 2.0

bug:30943280
Change-Id: Iee841b0bfff4fea583d3c27ecad7c766ebdd0964
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index b087783..97a14af 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -16,8 +16,8 @@
 
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.android.contacts"
-    android:versionCode="20100"
-    android:versionName="2.1.0">
+    android:versionCode="20000"
+    android:versionName="2.0.0">
 
     <uses-sdk android:minSdkVersion="21" android:targetSdkVersion="25" />