Dispose of input event reciever along with monitor

Explicitly store a reference to the input event receiver so that
we can dispose of it at the same time as the input monitor.

Bug: 206809961
Fix: 206809961
Test: manual
(cherry picked from commit 33f94a43)
(cherry picked from commit 7625c271)
Merged-In: Id201891ffd546119b18b18b692dd87008f6735c2
Change-Id: Id201891ffd546119b18b18b692dd87008f6735c2