Remove the dependency on StatusBarManagerService from IMMS

This is a mechanical code clean up with no behavior change for
InputMethodManagerService.

An internal callback

  InputMethodManagerService#systemRunning(StatusBarManagerService)

originates from a quick feature work to show progress dialog for
booting after an upgrade [1].  Since then system server lifecycle
management has been consolidated [2][3][4], but the direct dependency
on StatusBarManagerService from InputMethodManagerService has been
there.

This CL replaces StatusBarManagerService with StatusBarManagerInternal
to remove such a direct dependency from InputMethodManagerService.

 [1]: I0e78439ccec3850fb67872c22f235bf12a158dae
      661cd52e
 [2]: I637ba28412793166cbf519273fdf022241159a92
      a0027153
 [3]: Iaacfee8d5f080a28d7cc606761f4624673ed390f
      ef2ea1fa
 [4]: Ic17667df60b30e5355b61a3601ad27a000cab3a3
      1e33dc8f

Bug: 234882948
Test: presubmit
Change-Id: Iacd258006df73090c16d3f3b813a5f0a8cec488d