Makes the multi-touch prevention only works for editable TextView.

The original logic of preventing the multi-touch issue for the edtiable
text view was introduced by ag/10930920.
Turns out the non-editable text views are affected.

The root cause of the issue is that:
 - the ACTION_DOWN/ACTION_UP events, as well as ACTION_PONITER_DOWN /
   ACTION_POINTER_UP, could be generated by different fingers,
 - and View#onTouchEvent() gets muted when isFromPrimePointer() == false,
 - so that no gesture is generated, e.g. click, long press, etc.

Note that View#onTouchEvent() is necessary to be muted to prevent long press
on text or scrolling while dragging the insertion handle view.

Bug: 169288151
Change-Id: Ia763e94be727ad23bb13839f146293f1579d03ec
(cherry picked from commit 265096d9dac9cdfdce11f24f1b840b3139ea6fc0)
diff --git a/core/java/android/widget/TextView.java b/core/java/android/widget/TextView.java
index e16bf5a..5870ae7 100644
--- a/core/java/android/widget/TextView.java
+++ b/core/java/android/widget/TextView.java
@@ -11009,12 +11009,12 @@
                     MotionEvent.actionToString(event.getActionMasked()),
                     event.getX(), event.getY());
         }
-        if (!isFromPrimePointer(event, false)) {
-            return true;
-        }
-
         final int action = event.getActionMasked();
         if (mEditor != null) {
+            if (!isFromPrimePointer(event, false)) {
+                return true;
+            }
+
             mEditor.onTouchEvent(event);
 
             if (mEditor.mInsertionPointCursorController != null