Address ghost spots that show up after touchscreen is re-enabled

When touches are cancelled as a result of a touchscreen being disabled,
the pointers that were down when the touchscreen was disabled show up as
touch spots briefly while a new pointer goes down after the touchscreen
is enabled. Remove these ghost touches.

Bug: 216718625
Test: manual, see bug
Change-Id: I4fa381da9ca0e285dff4b405cad644fcea840d9e
diff --git a/services/inputflinger/reader/mapper/TouchInputMapper.cpp b/services/inputflinger/reader/mapper/TouchInputMapper.cpp
index c1934ff..637b1cb 100644
--- a/services/inputflinger/reader/mapper/TouchInputMapper.cpp
+++ b/services/inputflinger/reader/mapper/TouchInputMapper.cpp
@@ -1657,9 +1657,8 @@
 
         dispatchPointerUsage(when, readTime, policyFlags, pointerUsage);
     } else {
-        updateTouchSpots();
-
         if (!mCurrentMotionAborted) {
+            updateTouchSpots();
             dispatchButtonRelease(when, readTime, policyFlags);
             dispatchHoverExit(when, readTime, policyFlags);
             dispatchTouches(when, readTime, policyFlags);