Add HIDE_REMOVE_CLIENT into InputMethodDebug

CL [1] introduced the HIDE_REMOVE_CLIENT reason in
SoftInputShowHideReason.

Add this reason into InputMethodDebug to avoid dump
unknown reason unexpectedly.

[1]: Ifb91111f7136952462678ff6d0a5e917abb5005e

Bug: 167780081
Test: atest InputMethodDebugTest
Change-Id: I23a8deea66600e3e31bdcb5fbf8fb87d91c57e4d