The ComposerService object wasn't watching for SurfaceFlinger
restarts, which doesn't usually matter because the app framework
restarts when SurfaceFlinger dies. However, mediaserver continues
to run, which means its ComposerService object was trying to use
a dead handle, and playback of DRM movies was failing.
This adds a DeathRecipient listener and some logic to re-establish
the SurfaceFlinger connection.
Bug 6645813
Change-Id: I07581b881d3835601aa57d5358c8259d93bc4515
6652b3edcb