To update app icon so it matches the official Google Messages icon

[jed84]

Context
Google Messages has its icon updated from a while, but Android Messages Desktop did not reflect the change so far.
This ticket is a request to update the currently used icon to the latest one so it matched the one used in the official Android app.

[OrangeDrangon]

Does google provide a license to use this Logo? It is my understanding the current I cons are original works.

[large-farva]

It's Apache 2.0. You're good to throw it in there.

[LanikSJ]

This was discussed previously in #406