SurfaceControlViewHost: Let ViewRoot release control.

In SurfaceControlViewHost#release we currently immediately
release mSurfaceControl and then call ViewRootImpl#doDie.
However doDie executes on a handler so the ViewRootImpl may try
and use the SurfaceControl between posting and executing
the message. Actually this release is totally erroneous,
mSurfaceControl is the same object used by the ViewRootImpl
and the ViewRootImpl will release it when processing
doDie().

Bug: 155575445
Test: Existing tests pass
Change-Id: I6a4bf41ba38636ff884aa73d2653b1bab6958b00