Increase timeout when uncrypting OTA

Larger OTAs (750 MB tested) are taking 3-4 minutes
to write, due to the O_SYNC needed to ensure that
the data is actually committed to disk prior to
reboot.

Bug: 18750317
Change-Id: Idfab3ffd0276df4548f69a09c72ad6f4a344b6e6
(cherry picked from commit 01c06dfb07)

services/core/java/com/android/server/power/PowerManagerService.java

@@ -2293,9 +2293,9 @@ public final class PowerManagerService extends SystemService
             //
             // This preparation can take more than 20 seconds if
             // there's a very large update package, so lengthen the
-            // timeout.
+            // timeout.  We have seen 750MB packages take 3-4 minutes
             SystemProperties.set("ctl.start", "pre-recovery");
-            duration = 120 * 1000L;
+            duration = 300 * 1000L;
         } else {
             SystemProperties.set("sys.powerctl", "reboot," + reason);
             duration = 20 * 1000L;