make 15m planning interval on block scheduler the default

Author: owen-d

docs/sources/shared/configuration.md

@@ -216,7 +216,7 @@ block_scheduler:
 
   # How often the scheduler should plan jobs.
   # CLI flag: -block-scheduler.interval
-  [interval: <duration> | default = 5m]
+  [interval: <duration> | default = 15m]
 
   # Lookback period used by the scheduler to plan jobs when the consumer group
   # has no commits. 0 consumes from the start of the partition.

pkg/blockbuilder/scheduler/scheduler.go

@@ -35,7 +35,7 @@ type Config struct {
 }
 
 func (cfg *Config) RegisterFlagsWithPrefix(prefix string, f *flag.FlagSet) {
-	f.DurationVar(&cfg.Interval, prefix+"interval", 5*time.Minute, "How often the scheduler should plan jobs.")
+	f.DurationVar(&cfg.Interval, prefix+"interval", 15*time.Minute, "How often the scheduler should plan jobs.")
 	f.StringVar(&cfg.ConsumerGroup, prefix+"consumer-group", "block-scheduler", "Consumer group used by block scheduler to track the last consumed offset.")
 	f.DurationVar(&cfg.LookbackPeriod, prefix+"lookback-period", 0, "Lookback period used by the scheduler to plan jobs when the consumer group has no commits. 0 consumes from the start of the partition.")
 	f.StringVar(