The 'feed' button appears when you try to feed a wolf with raw and cooked fish. However, the wiki says that wolves can be fed with any kind of meat OTHER THAN fish.
Device: Lenovo A5500-HV
MCPE-13421
Wolves can be fed with raw and cooked fish
Resolved
Fixed
2
Lionel Alanguilan
(Unassigned)
Unconfirmed
Tablet - Android - Other (Specify in description)
Android 4.4.2
0.14.0 Beta 6, 0.14.3, 0.15.0, 0.15.1 Beta 1, 0.15.1, ..., 0.15.3, 0.15.4, 0.15.6, 0.15.90.0, 0.15.7
0.15.90.7
Retrieved
also happened to me