Raise exception if can't dup InputChannel

We are seeing a crash where mInputChannel inside NativeInputChannel is
null.
When we are about to initialize NativeInputChannel with a null
InputChannel, raise a jni exception. This would help us bring attention
to this line of code.

Bug: 141111452
Test: none
Change-Id: I17d484dc6a44fce7f235125fcc17e63b69c0d789