Don't set timeout when showing CDM UI

Since it's a UI-based operation, there's no need to set a timeout.

Bug: 167592848
Test: manual; atest CompanionDeviceManagerTest
Change-Id: I3c399858064eefc1eaa867201551f1652198cb06
(cherry picked from commit 9820b8ffb5be7ea80e0ee478373d6fffaec11bdc)
diff --git a/services/companion/java/com/android/server/companion/CompanionDeviceManagerService.java b/services/companion/java/com/android/server/companion/CompanionDeviceManagerService.java
index 29fc1674..a31050c 100644
--- a/services/companion/java/com/android/server/companion/CompanionDeviceManagerService.java
+++ b/services/companion/java/com/android/server/companion/CompanionDeviceManagerService.java
@@ -308,7 +308,7 @@
                     AndroidFuture<Association> future = new AndroidFuture<>();
                     service.startDiscovery(request, callingPackage, callback, future);
                     return future;
-                }).whenComplete(uncheckExceptions((association, err) -> {
+                }).cancelTimeout().whenComplete(uncheckExceptions((association, err) -> {
                     if (err == null) {
                         addAssociation(association);
                     } else {