The MediaViewer and MultimediaViewer* instruments were disabled circa
October 2021 in Ie7dd8739efc.
This patch removes those instruments and any supporting code and data.
Notably, this patch does not remove the mw.mmv.logging.ViewLogger
instrument, which is responsible for logging image views.
Bug: T310890
Change-Id: I97d41be93849b2ae9d1adba6660546ea716657fd