Use std::shared_ptr for InputChannel

Modernize the code by moving away from RefBase.
We can further improve this by switching to unique_ptr in some places.
Current refactor is to get off of RefBase only.

Test: interact with cf after device boots
Bug: 142581626
Change-Id: Ib90fc721970113310b87411bcc2ba62e30ddfd01
diff --git a/services/inputflinger/dispatcher/Monitor.cpp b/services/inputflinger/dispatcher/Monitor.cpp
index 289b084..b347674 100644
--- a/services/inputflinger/dispatcher/Monitor.cpp
+++ b/services/inputflinger/dispatcher/Monitor.cpp
@@ -19,7 +19,7 @@
 namespace android::inputdispatcher {
 
 // --- Monitor ---
-Monitor::Monitor(const sp<InputChannel>& inputChannel) : inputChannel(inputChannel) {}
+Monitor::Monitor(const std::shared_ptr<InputChannel>& inputChannel) : inputChannel(inputChannel) {}
 
 // --- TouchedMonitor ---
 TouchedMonitor::TouchedMonitor(const Monitor& monitor, float xOffset, float yOffset)