Use ftl::Flags for InputTarget flags

These flags will now be type-safe.

Bug: 211379801
Test: m inputflinger_tests && adb sync data && adb shell -t /data/nativetest64/inputflinger_tests/inputflinger_tests
Change-Id: If1835151df74cfebf39ec3471f826082bea30e26
diff --git a/services/inputflinger/dispatcher/TouchState.h b/services/inputflinger/dispatcher/TouchState.h
index e4e59fd..77c1cdf 100644
--- a/services/inputflinger/dispatcher/TouchState.h
+++ b/services/inputflinger/dispatcher/TouchState.h
@@ -40,7 +40,7 @@
 
     void reset();
     void addOrUpdateWindow(const sp<android::gui::WindowInfoHandle>& windowHandle,
-                           int32_t targetFlags, BitSet32 pointerIds,
+                           ftl::Flags<InputTarget::Flags> targetFlags, BitSet32 pointerIds,
                            std::optional<nsecs_t> eventTime = std::nullopt);
     void removeWindowByToken(const sp<IBinder>& token);
     void filterNonAsIsTouchWindows();