Fix issue #27653326: Sync doesn't work in doze maintenance

Add a (configurable) delay between when we start a maintenance
window until the minimum time we will end it.

Also switch to using the alarm manager callback API.  (Yay!)

Also fix a little printing problem in the alarm manager dump
so we put the package name and not some class hash in the
summary string of an alarm entry.

Change-Id: I4281e5c80bc8b26ebc1fb6f603ec33ec0e379daa
diff --git a/services/core/java/com/android/server/AlarmManagerService.java b/services/core/java/com/android/server/AlarmManagerService.java
index c5a210c..7da247a 100644
--- a/services/core/java/com/android/server/AlarmManagerService.java
+++ b/services/core/java/com/android/server/AlarmManagerService.java
@@ -2297,7 +2297,7 @@
             if (operation != null) {
                 sb.append(operation.getTargetPackage());
             } else {
-                sb.append(listener.asBinder().toString());
+                sb.append(packageName);
             }
             sb.append('}');
             return sb.toString();