Only clear A11y focus in date picker on MR1. Expose stable IDs.

BUG: 8659961
Change-Id: I15be1c7208b75f1e85d644299437500c389f45ee

src/com/android/datetimepicker/date/DayPickerView.java

@@ -18,6 +18,7 @@ package com.android.datetimepicker.date;
 
 import android.annotation.SuppressLint;
 import android.content.Context;
+import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
 import android.util.AttributeSet;
@@ -382,8 +383,10 @@ public class DayPickerView extends ListView implements OnScrollListener, OnDateC
             if (child instanceof SimpleMonthView) {
                 final CalendarDay focus = ((SimpleMonthView) child).getAccessibilityFocus();
                 if (focus != null) {
-                    // Clear focus to avoid ListView bug in Jelly Bean MR1.
-                    ((SimpleMonthView) child).clearAccessibilityFocus();
+                    if (Build.VERSION.SDK_INT == Build.VERSION_CODES.JELLY_BEAN_MR1) {
+                        // Clear focus to avoid ListView bug in Jelly Bean MR1.
+                        ((SimpleMonthView) child).clearAccessibilityFocus();
+                    }
                     return focus;
                 }
             }

src/com/android/datetimepicker/date/SimpleMonthAdapter.java

@@ -148,6 +148,11 @@ public class SimpleMonthAdapter extends BaseAdapter implements OnDayClickListene
         return position;
     }
 
+    @Override
+    public boolean hasStableIds() {
+        return true;
+    }
+
     @SuppressLint("NewApi")
     @SuppressWarnings("unchecked")
     @Override