[appmgr] disable storage watchdog

The current implementation of the storage watchdogs checks usage against
minfs allocation size, whereas it should be checking it against the
maximum size of the partition.

CF-736 #comment

Change-Id: Ice62267d9d3dadd076745d4b87c42aef734b6882

garnet/bin/appmgr/appmgr.cc

@@ -27,7 +27,8 @@ Appmgr::Appmgr(async_dispatcher_t* dispatcher, AppmgrArgs args)
       sysmgr_permanently_failed_(false),
       storage_watchdog_(StorageWatchdog("/data", "/data/cache")) {
   // 0. Start storage watchdog for cache storage
-  storage_watchdog_.Run(dispatcher);
+  // TODO(CF-736): improve StorageWatchdog::GetStorageUsage and reenable
+  // storage_watchdog_.Run(dispatcher);
   // 1. Create root realm.
   RealmArgs realm_args = RealmArgs::Make(
       nullptr, kRootLabel, "/data", "/data/cache", args.environment_services,