Remove reference to dead-end IntDef

As per API Council feedback, remove reference to an
intdef that doesn't survive the process of conversion to
docs. It isn't necessary because metalava sorcery automatically
generates a reference to the enum and appends it, albeit without
any punctuation, to the end of the method description.

Bug: 161206874
Test: make offline-sdk-docs
Change-Id: I53d98c56ba8bb1172c90e49b5831e33876c302e9