AnimatedAdapter shouldn't show header if there is no content

Instead of having a separate getContentCount, simply have the
count return 0 if the content count is 0. If the content count
is nonempty, then add the header count to the result.

This effectively prevents the headers from ever rendering unless
there is some content underneath.

b/17306351

Change-Id: I04a577d4fb3e54ea201214da2ec1aac74d3a27d2
2 files changed