Is it always necessary that an expandable list should have an indication to show that that it is expandable?

Recently I've been designing a mockup for an android app (material designed) where I use a list to show number of entries. And the list is expandable.

Is it always necessary to indicate to the end user that the list is expandable?

I've a count on the parent list item which shows the number of items it'll have if expanded.

I also many other data to be displayed along with it so was searching a work around.

What I tried doing is using a right chevron at the end of the list that transforms 90 degree clock-wise as I expand.

But this along with the count doesn't go much pretty.

Please suggest what should be done instead.

P.S I've already rejected the choice of using the list as shown on google material design page (or to simplify as used in app: Inbox by google.)