Show glowpad for call waiting calls

Two things were happening:
1. AnswerPresenter stopped listening to call event after the first
incoming call
2. It was not checking for CALL_WAITING && INCOMING as valid incoming
call states.

fix both.

bug: 10538445
Change-Id: I491f2381c33c431f0cbfcc0000f50efdc107cce9
1 file changed
tree: e9784a47888cc66c4e054b9537f7425e9d6771ab
  1. InCallUI/