Merge cherrypicks of [6391991, 6392011, 6391992, 6391993, 6392031, 6392051, 6392052, 6392091, 6392111, 6392032, 6391994, 6391995, 6391996, 6391997, 6391998, 6391999, 6392000, 6392001, 6392002, 6392003, 6392004, 6392005, 6392006, 6392112, 6392113, 6392151, 6392152] into pi-qpr2-release

Change-Id: I3808395b49e1416d2f5107d926b1b713e17828b7
diff --git a/services/core/java/com/android/server/AlarmManagerService.java b/services/core/java/com/android/server/AlarmManagerService.java
index f79a51b..47b646c 100644
--- a/services/core/java/com/android/server/AlarmManagerService.java
+++ b/services/core/java/com/android/server/AlarmManagerService.java
@@ -48,6 +48,7 @@
 import android.database.ContentObserver;
 import android.net.Uri;
 import android.os.Binder;
+import android.os.Build;
 import android.os.Bundle;
 import android.os.Environment;
 import android.os.Handler;
@@ -1288,9 +1289,13 @@
         // because kernel doesn't keep this after reboot
         setTimeZoneImpl(SystemProperties.get(TIMEZONE_PROPERTY));
 
-        // Also sure that we're booting with a halfway sensible current time
         if (mNativeData != 0) {
-            final long systemBuildTime = Environment.getRootDirectory().lastModified();
+            // Ensure that we're booting with a halfway sensible current time.  Use the
+            // most recent of Build.TIME, the root file system's timestamp, and the
+            // value of the ro.build.date.utc system property (which is in seconds).
+            final long systemBuildTime =  Long.max(
+                    1000L * SystemProperties.getLong("ro.build.date.utc", -1L),
+                    Long.max(Environment.getRootDirectory().lastModified(), Build.TIME));
             if (System.currentTimeMillis() < systemBuildTime) {
                 Slog.i(TAG, "Current time only " + System.currentTimeMillis()
                         + ", advancing to build time " + systemBuildTime);