manager: in dump, show controllers in "Delegate:"

manager: in dump, show controllers in "Delegate:"

After Delegate= was converted from boolean to a controller list, the dump
output was changed to have a separate line about the delegated controllers:

  ...
  DevicePolicy: auto
  DisableControllers:
  Delegate: yes
  ManagedOOMSwap: auto
  ManagedOOMMemoryPressure: auto
  ManagedOOMMemoryPressureLimit: 0.00%
  ManagedOOMPreference: none
  DelegateControllers: cpu memory pids
  ...

The line with "Delegate:" is redundant, it effectively shows if
"DelegateControllers:" is non-empty. It is nicer to keep the lines
about controllers adjacent. And to avoid duplicate output, Delegate:
will now show which controllers are enabled. This makes the output
for that line again match the configuration stanza Delegate=:

  DisableControllers:
  Delegate: cpu io memory pids
  ManagedOOMSwap: auto
  ManagedOOMMemoryPressure: auto
  ManagedOOMMemoryPressureLimit: 0.00%
  ManagedOOMPreference: none
  MemoryPressureWatch: auto
  MemoryPressureThresholdSec: 100ms

Dump output is for debugging, we don't need to maintain strict
backwards-compat.