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/benchmarks/InputDispatcher_benchmarks.cpp b/services/inputflinger/benchmarks/InputDispatcher_benchmarks.cpp
index a15b7b2..3d66d30 100644
--- a/services/inputflinger/benchmarks/InputDispatcher_benchmarks.cpp
+++ b/services/inputflinger/benchmarks/InputDispatcher_benchmarks.cpp
@@ -135,7 +135,7 @@
     virtual ~FakeInputReceiver() {}
 
     sp<InputDispatcher> mDispatcher;
-    sp<InputChannel> mServerChannel, mClientChannel;
+    std::shared_ptr<InputChannel> mServerChannel, mClientChannel;
     std::unique_ptr<InputConsumer> mConsumer;
     PreallocatedInputEventFactory mEventFactory;
 };