Refactor ApfFilter constructor

* Shortened try-catch block in maybeStartFilter() (renamed to
  startFilter) to only cover socket creation and binding.
* Removed the redundant mIsRunning flag.
* Added Log.wtf() for incomplete initialization scenarios.
* Made mHardwareAddress final.

Bug: 348528574
Test: TH
Change-Id: Ia22ae6f7ef62fab3182dac9d2bf13f144f6261ed
2 files changed