Add Media Management Apps activity in Special App Access

Add a settings page to control the permission MANAGE_MEDIA in Special
App Access. Apps can launch it by ACTION_REQUEST_MANAGE_MEDIA.

Test: m -j RunSettingsRoboTests ROBOTEST_FILTER=MediaManagementAppsDetailsTest
Test: m -j RunSettingsRoboTests
Test: manual
Bug: 181112025
Change-Id: Id7587cf179b8c5adbfd6477ca9c2d4a20a9852bb