Add page creation latency for updatePreferenceStates

- The updatePreferenceStates is called in the onResume. Here creates a new enum to
  record the elapsed time.

Bug: 137558156
Test: make RunSettingsRoboTests -j ROBOTEST_FILTER=com.android.settings.dashboard
Test: make RunSettingsRoboTests -j ROBOTEST_FILTER=com.android.settings.core
Change-Id: I02bdbeecd61fbc0082eea19ea64cbfe7541a6970
2 files changed