This isn’t going to be automatic one way or the other. If Cruz wins Indiana and does o.k. in California, the Cruz forces a second ballot (unless something really unusual happens). If Trump wins Indiana and/or does very well in California, Trump, then Trump wins of the first ballot (unless something really unusual happens).
BOTTOM LINE: Neither side should tai anything for granted.
I will put aside for a minute that Cruz is now mathematically eliminated... But, would you agree if Cruz loses Indiana, that he needs to drop out?