Mark Media APEX as visible

Linkerconfig is going to remove all hard-coded dependencies from APEX
modules and let APEX modules specify its own requirements. As part of
it, this change adds a new configuration file for linkerconfig and let
it aware that media APEX should be visible from all sections.

Bug: 167946001
Test: atest passed
Change-Id: Id1ef65a0b804756a27440c4c1a4c38fd775fccd9