ART: Decrease dex2oat watchdog timeout

Keep the dex2oat watchdog timeout lower than the package manager
timeout, so that dex2oat kills itself before the system server
watchdog kills the system because of the long installation.

Bug: 23629410

(cherry picked from commit 540138ae55ac1909606a436d7f52e20146c56657)

Change-Id: I5faa23a1715736a1c2ba3f302a6ee41130d3fbae
diff --git a/dex2oat/dex2oat.cc b/dex2oat/dex2oat.cc
index e913c20..c51c317 100644
--- a/dex2oat/dex2oat.cc
+++ b/dex2oat/dex2oat.cc
@@ -433,8 +433,10 @@
   // Debug builds are slower so they have larger timeouts.
   static constexpr int64_t kSlowdownFactor = kIsDebugBuild ? 5U : 1U;
 
-  // 10 minutes scaled by kSlowdownFactor.
-  static constexpr int64_t kWatchDogTimeoutSeconds = kSlowdownFactor * 10 * 60;
+  // 9.5 minutes scaled by kSlowdownFactor. This is slightly smaller than the Package Manager
+  // watchdog (PackageManagerService.WATCHDOG_TIMEOUT, 10 minutes), so that dex2oat will abort
+  // itself before that watchdog would take down the system server.
+  static constexpr int64_t kWatchDogTimeoutSeconds = kSlowdownFactor * (9 * 60 + 30);
 
   bool is_watch_dog_enabled_;
   bool shutting_down_;