Midnight should mean midnight

...not noon-or-midnight.  Fix the initial fstrim delay to properly refer
to midnight rather than ambiguous 12-hour "zero" so that fstrim job
consideration always starts overnight rather than possibly at the following
day's noon, depending on when the device was booted.

Bug 18076397

Change-Id: Ife3cd5bdeb14c7832b6e2a2de88dcfd1ba731b67

services/core/java/com/android/server/MountServiceIdler.java

@@ -98,7 +98,7 @@ public class MountServiceIdler extends JobService {
     private static Calendar tomorrowMidnight() {
         Calendar calendar = Calendar.getInstance();
         calendar.setTimeInMillis(System.currentTimeMillis());
-        calendar.set(Calendar.HOUR, 0);
+        calendar.set(Calendar.HOUR_OF_DAY, 0);
         calendar.set(Calendar.MINUTE, 0);
         calendar.set(Calendar.SECOND, 0);
         calendar.set(Calendar.MILLISECOND, 0);