I have no idea which is 'better' per se as that is a subjective term so only you can decide that, but from an objective point of view,;
Java is better for Android, while Obj..C is better for iOS.
However learning both "Obj.. C" and Java would be advantageous if you intend to target both operating systems. The semantics and structure of both languages are broadly similar so knowing either should make learning the other is relatively straightforward.
Chris.
Indifference will be the downfall of mankind, but who cares?
Time flies like an arrow, however, fruit flies like a banana.
Never mind this jesus character, stars had to die for me to live.