Improve timing in OfflineServiceControllerTest

Some of the tests are flaky.
Significantly increased timeouts will give us confidence that
tests are failing due to a defect and not due to a test taking a little
bit more time than usual.

PiperOrigin-RevId: 547819011

internal/platform/exception.h

@@ -34,6 +34,7 @@ struct Exception {
                              // illegal chars
   };
   bool Ok() const { return value == kSuccess; }
+  explicit operator bool() const { return Ok(); }
   bool Raised() const { return !Ok(); }
   bool Raised(Value val) const { return value == val; }
   Value value{kFailed};