Fix backup tool:

Thanks to CyanogenMod:

build: edify: use set_metadata for backuptool:
https://github.com/CyanogenMod/android_build/commit/d29ee663893868912b4b813e2900c0b91b1aa9c2

ota: Include copies of the recovery scripts even if shipping in block mode:
https://github.com/CyanogenMod/android_build/commit/65004accec22317d8d53b26cef9072e159b4863e

ota: Fix recovery-script cleanups in block mode:
https://github.com/CyanogenMod/android_build/commit/49473e55938a413d59aca4e383beffc3dd2e7f74