Restrict access to hwservicemanager

This adds fine-grained policy about who can register and find which
HwBinder services in hwservicemanager.

Test: Play movie in Netflix and Google Play Movies
Test: Play video in YouTube app and YouTube web page
Test: In Google Camera app, take photo (HDR+ and conventional),
      record video (slow motion and normal), and check that photos
      look fine and videos play back with sound.
Test: Cast screen to a Google Cast device
Test: Get location fix in Google Maps
Test: Make and receive a phone call, check that sound works both ways
      and that disconnecting the call frome either end works fine.
Test: Run RsHelloCompute RenderScript demo app
Test: Run fast subset of media CTS tests:
      make and install CtsMediaTestCases.apk
      adb shell am instrument -e size small \
          -w 'android.media.cts/android.support.test.runner.AndroidJUnitRunner'
Test: Play music using Google Play music
Test: Adjust screen brightness via the slider in Quick Settings
Test: adb bugreport
Test: Enroll in fingerprint screen unlock, unlock screen using
      fingerprint
Test: Apply OTA update:
      Make some visible change, e.g., rename Settings app.
      make otatools && \
      make dist
      Ensure device has network connectivity
      ota_call.py -s <serial here> --file out/dist/sailfish-ota-*.zip
      Confirm the change is now live on the device
Bug: 34454312
Change-Id: Iecf74000e6c68f01299667486f3c767912c076d3