Notify MetricsCollector of device interaction from Dispatcher

InputDispatcher will notify the metrics collector whenever an
interaction occurs between an input device and a UID through its policy.

Bug: 275726706
Test: atest inputflinger_tests
Test: statsd_testdrive
Change-Id: Ic62b351263542577328db00c7feb5ff6042f6fe0
diff --git a/services/inputflinger/InputManager.cpp b/services/inputflinger/InputManager.cpp
index 863b483..1a9f47d 100644
--- a/services/inputflinger/InputManager.cpp
+++ b/services/inputflinger/InputManager.cpp
@@ -127,6 +127,10 @@
     return *mProcessor;
 }
 
+InputDeviceMetricsCollectorInterface& InputManager::getMetricsCollector() {
+    return *mCollector;
+}
+
 InputDispatcherInterface& InputManager::getDispatcher() {
     return *mDispatcher;
 }