InputMapper: pass RawEvent references instead of pointers

We never pass null values here, so changing to references makes this
clearer.

Change-Id: I82d5359e244a93560bcbef477c89fef016168abb
Test: atest inputflinger_test
Test: m checkinput
Test: manually test basic functionality on a multi-touch screen, touchpad, mouse, and drawing tablet
Bug: 245989146
Flag: EXEMPT refactor
diff --git a/services/inputflinger/tests/fuzzers/KeyboardInputFuzzer.cpp b/services/inputflinger/tests/fuzzers/KeyboardInputFuzzer.cpp
index 922cbdf..8c3189e 100644
--- a/services/inputflinger/tests/fuzzers/KeyboardInputFuzzer.cpp
+++ b/services/inputflinger/tests/fuzzers/KeyboardInputFuzzer.cpp
@@ -80,7 +80,7 @@
                 },
                 [&]() -> void {
                     RawEvent rawEvent = getFuzzedRawEvent(*fdp);
-                    std::list<NotifyArgs> unused = mapper.process(&rawEvent);
+                    std::list<NotifyArgs> unused = mapper.process(rawEvent);
                 },
                 [&]() -> void {
                     mapper.getKeyCodeState(fdp->ConsumeIntegral<uint32_t>(),