Fix account selector UI in Contact editor.

1) Hide the "Saving to" account container when there're both
read-only and writable contacts.
2) Add more space between name field and whatever are above it.
3) Show linked contacts selector when there's only one read-only.

BUG 25219324

Change-Id: I9229132a833400de5cb542bc5363a4e3f36c9d1a
diff --git a/res/layout/compact_account_info.xml b/res/layout/compact_account_info.xml
index 43686f3..a31e12d 100644
--- a/res/layout/compact_account_info.xml
+++ b/res/layout/compact_account_info.xml
@@ -24,6 +24,7 @@
         android:minHeight="@dimen/editor_min_line_item_height"
         android:orientation="horizontal"
         android:background="?android:attr/selectableItemBackground"
+        android:layout_marginBottom="@dimen/compact_editor_name_top_margin"
         android:visibility="gone"
         >