user configureable init.d

cherry picked from:
  - Configurable init.d: https://github.com/PAC-man/android_vendor_pac/commit/347cfd775401e64d9554a1e0b1315a4c5e23de42
  - Port Forward Configurable Init.d and add new tweaks: https://github.com/PAC-man/android_vendor_pac/commit/cfd43f8bad5190d0f63c14685f218c7411b2781a

Change-Id: I10ca695de7cc505b0306b3eeb88d7d9fa77c2023