Fix MotionEvent pointer API.

Ooops.  The API said that the pointer down and up actions contained
the pointer id, but it is actually the index.  Actually it makes
much more sense for it to be the index, and those ACTION_POINTER_1_DOWN
etc. constants were stupid.
diff --git a/common/java/com/android/common/ui/PointerLocationView.java b/common/java/com/android/common/ui/PointerLocationView.java
index e83c5ae..7bdb0bc 100644
--- a/common/java/com/android/common/ui/PointerLocationView.java
+++ b/common/java/com/android/common/ui/PointerLocationView.java
@@ -234,8 +234,9 @@
             }
             
             if ((action&MotionEvent.ACTION_MASK) == MotionEvent.ACTION_POINTER_DOWN) {
-                final int id = (action&MotionEvent.ACTION_POINTER_ID_MASK)
-                        >> MotionEvent.ACTION_POINTER_ID_SHIFT;
+                final int index = (action&MotionEvent.ACTION_POINTER_INDEX_MASK)
+                        >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
+                final int id = event.getPointerId(index);
                 while (NP <= id) {
                     PointerState ps = new PointerState();
                     ps.mVelocity = VelocityTracker.obtain();
@@ -260,13 +261,14 @@
             }
             
             for (int i=0; i<NI; i++) {
-                final PointerState ps = mPointers.get(event.getPointerId(i));
+                final int id = event.getPointerId(i);
+                final PointerState ps = mPointers.get(id);
                 ps.mVelocity.addMovement(event);
                 ps.mVelocity.computeCurrentVelocity(1);
                 final int N = event.getHistorySize();
                 for (int j=0; j<N; j++) {
                     if (mPrintCoords) {
-                        Log.i("Pointer", "Pointer " + (i+1) + ": ("
+                        Log.i("Pointer", "Pointer " + (id+1) + ": ("
                                 + event.getHistoricalX(i, j)
                                 + ", " + event.getHistoricalY(i, j) + ")"
                                 + " Prs=" + event.getHistoricalPressure(i, j)
@@ -276,7 +278,7 @@
                     ps.mYs.add(event.getHistoricalY(i, j));
                 }
                 if (mPrintCoords) {
-                    Log.i("Pointer", "Pointer " + (i+1) + ": ("
+                    Log.i("Pointer", "Pointer " + (id+1) + ": ("
                             + event.getX(i) + ", " + event.getY(i) + ")"
                             + " Prs=" + event.getPressure(i)
                             + " Size=" + event.getSize(i));
@@ -293,8 +295,9 @@
             }
             
             if ((action&MotionEvent.ACTION_MASK) == MotionEvent.ACTION_POINTER_UP) {
-                final int id = (action&MotionEvent.ACTION_POINTER_ID_MASK)
-                        >> MotionEvent.ACTION_POINTER_ID_SHIFT;
+                final int index = (action&MotionEvent.ACTION_POINTER_INDEX_MASK)
+                        >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
+                final int id = event.getPointerId(index);
                 final PointerState ps = mPointers.get(id);
                 ps.mXs.add(Float.NaN);
                 ps.mYs.add(Float.NaN);
@@ -306,11 +309,12 @@
             
             if (action == MotionEvent.ACTION_UP) {
                 for (int i=0; i<NI; i++) {
-                    final PointerState ps = mPointers.get(event.getPointerId(i));
+                    final int id = event.getPointerId(i);
+                    final PointerState ps = mPointers.get(id);
                     if (ps.mCurDown) {
                         ps.mCurDown = false;
                         if (mPrintCoords) {
-                            Log.i("Pointer", "Pointer " + (i+1) + ": UP");
+                            Log.i("Pointer", "Pointer " + (id+1) + ": UP");
                         }
                     }
                 }