Fixed a bug with a legacy notification API

When using setLatestEventInfo the icons would not be shown
at all anymore, leading to a crash if they were grouped.
This CL makes sure the smallIcon is always set even for those
legacy apps.
It also fixes the usage of setShow when, as legacy apps wouldn't
have the time anymore.

Change-Id: I2645175b2adabcedbbfec7a502b89d143d2b9bd3
Fixes: 29255365
Fixes: 27430676

core/java/android/app/Notification.java

@@ -1986,6 +1986,10 @@ public class Notification implements Parcelable
                     new Throwable());
         }
 
+        if (context.getApplicationInfo().targetSdkVersion < Build.VERSION_CODES.N) {
+            extras.putBoolean(EXTRA_SHOW_WHEN, true);
+        }
+
         // ensure that any information already set directly is preserved
         final Notification.Builder builder = new Notification.Builder(context, this);
 
@@ -2269,6 +2273,14 @@ public class Notification implements Parcelable
                     Collections.addAll(mPersonList, mN.extras.getStringArray(EXTRA_PEOPLE));
                 }
 
+                if (mN.getSmallIcon() == null && mN.icon != 0) {
+                    setSmallIcon(mN.icon);
+                }
+
+                if (mN.getLargeIcon() == null && mN.largeIcon != null) {
+                    setLargeIcon(mN.largeIcon);
+                }
+
                 String templateClass = mN.extras.getString(EXTRA_TEMPLATE);
                 if (!TextUtils.isEmpty(templateClass)) {
                     final Class<? extends Style> styleClass