FocusResolver: Clean up focus requests and results when a display is removed

Prevents FocusResolver from leaking focus requests and results as
displays are added and removed.

Test: atest inputflinger_tests
Fixes: 188008394
Change-Id: I635b9becf91056fd540ab9d9546dd67a09324fc6
diff --git a/services/inputflinger/dispatcher/FocusResolver.cpp b/services/inputflinger/dispatcher/FocusResolver.cpp
index 2db8c13..fb19435 100644
--- a/services/inputflinger/dispatcher/FocusResolver.cpp
+++ b/services/inputflinger/dispatcher/FocusResolver.cpp
@@ -216,4 +216,9 @@
     return dump;
 }
 
+void FocusResolver::displayRemoved(int32_t displayId) {
+    mFocusRequestByDisplay.erase(displayId);
+    mLastFocusResultByDisplay.erase(displayId);
+}
+
 } // namespace android::inputdispatcher