Allow invoke in all the player states except idle and error.

Previously invoke would work only after prepare but not
when the player is in play or pause state (for instance).
This new change just check that the player has been initialized
and is not in the error state.

Bug:2488931
Change-Id: I9b9f3679593a3b7697c1a84d993fdcd7e1693a90
1 file changed