Optimize framework's PNG resources

The images that framework uses are not optimized, and were created
quite many years ago, which means that they didn't benefit from the
advanced PNG tooling we enjoy today.

I ran optimage on all files, an internal command line tool that
will increase the compression of PNG files without losing any
information.

Bug: 265292276
Test: build and tested in device; checked that mouse cursor images
look the same.

Change-Id: Ie549b7bfcbfdab466090e4779a385c20b50c2ce6