Revert "trancoding: lazy-start transcoding service" This reverts commit 0621358a526d2ede2e675a1992ce304bcdcb83b8. Reason for revert: change to conditional start. Bug: 187271658 Test: atest MediaTranscodeManagerTest; unit tests Change-Id: Iba169a3b50e37b72fab4e354480451cf05ab5be5