Increase exponential backoff maximum time to 26h on Brillo.

Brillo devices ping Omaha every 5 hours and will increase that value on
an exponential backoff schedule when receiving an error 500 or 503. For
Chrome OS devices, the ping happens every 45 minutes, so the limit on
the exponential backoff is set to 4 hours. This CL changes the limit on
Brillo to 26h, to maintain the proportion.

Bug: 24878416
Test: mm

Change-Id: Ie5ffe6e08a25c2c801ed1aa3b79cb6742cd07caa
diff --git a/update_manager/chromeos_policy.cc b/update_manager/chromeos_policy.cc
index 886ec06..3a81059 100644
--- a/update_manager/chromeos_policy.cc
+++ b/update_manager/chromeos_policy.cc
@@ -169,11 +169,12 @@
 // make the update check periodic interval configurable.
 #ifdef __ANDROID__
 const int ChromeOSPolicy::kTimeoutPeriodicInterval = 5 * 60 * 60;
+const int ChromeOSPolicy::kTimeoutMaxBackoffInterval = 26 * 60 * 60;
 #else
 const int ChromeOSPolicy::kTimeoutPeriodicInterval = 45 * 60;
+const int ChromeOSPolicy::kTimeoutMaxBackoffInterval = 4 * 60 * 60;
 #endif  // __ANDROID__
 
-const int ChromeOSPolicy::kTimeoutMaxBackoffInterval = 4 * 60 * 60;
 const int ChromeOSPolicy::kTimeoutRegularFuzz = 10 * 60;
 const int ChromeOSPolicy::kAttemptBackoffMaxIntervalInDays = 16;
 const int ChromeOSPolicy::kAttemptBackoffFuzzInHours = 12;