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/TouchedWindow.h b/services/inputflinger/dispatcher/TouchedWindow.h
index 0cc9999..dd08323 100644
--- a/services/inputflinger/dispatcher/TouchedWindow.h
+++ b/services/inputflinger/dispatcher/TouchedWindow.h
@@ -18,6 +18,7 @@
 
 #include <gui/WindowInfo.h>
 #include <utils/BitSet.h>
+#include "InputTarget.h"
 
 namespace android {
 
@@ -26,7 +27,7 @@
 // Focus tracking for touch.
 struct TouchedWindow {
     sp<gui::WindowInfoHandle> windowHandle;
-    int32_t targetFlags;
+    ftl::Flags<InputTarget::Flags> targetFlags;
     BitSet32 pointerIds;
     bool isPilferingPointers = false;
     // Time at which the first action down occurred on this window.