Don't track launch time for activity which won't resume

If "doResume" is false, it may only put an ActivityRecord with
INITIALIZING state on a background task. Then if the task is
moved to front after a long time, the launch time will be
unexpected long.

Also remove the parameter "doResume" of several methods which is
always true.

Bug: 204488635
Test: Start activity A. Press home key. A starts B after 5s.
      The launch will be blocked by background-activity-launch.
      Because there is an existing task for B, B will be put
      on the task silently without creating client side. Then
      when launching A again (or use recents to choose the task),
      The launch time should not include the duration since A
      starts B. The duration will count since the last time
      moving the task to front.
Change-Id: I63b11fc123c265b30159843285e6f5555b2fd440