internal/gomote: extend the gomote instance creation timeout

This extends the amount of time we spend waiting for a gomote instance
to be created.

Change-Id: Ica872dceff7ec19226022b1e83646ccdfb9c304e
Reviewed-on: https://go-review.googlesource.com/c/build/+/566955
Reviewed-by: Michael Pratt <mpratt@google.com>
Auto-Submit: Carlos Amedee <carlos@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

internal/gomote/swarming.go

@@ -816,7 +816,7 @@ func (ss *SwarmingServer) startNewSwarmingTask(ctx context.Context, name string,
 // waitForInstanceOrFailure waits for either the swarming task to enter a failed state or the successful connection from
 // a buildlet client.
 func (ss *SwarmingServer) waitForInstanceOrFailure(ctx context.Context, taskID, name string) (buildlet.Client, error) {
-	queryCtx, cancel := context.WithTimeout(ctx, 10*time.Minute)
+	queryCtx, cancel := context.WithTimeout(ctx, 25*time.Minute)
 
 	checkForTaskFailure := func(pollCtx context.Context) <-chan error {
 		errCh := make(chan error, 1)