keys: avoid duplicating recovery keys

Setting PRODUCT_EXTRA_RECOVERY_KEYS duplicates the default key and
makes it so we can't set an extra key earlier in the build

Change-Id: I239d9994d9ad40b1779877ea2e89b55bd02e4c00
ota: Allow devices to skip generation of recovery-from-boot.p

* Not all devices have a real recovery partition, so those devices
  should skip this generation step.

Change-Id: I4abc3f92b879e6997e4874543ec9772c3179b1d0
hardcode build user and host

Change-Id: I1b8132f11bb249dd7a950662c02898da9b4584c0
Take advantage of git-rerere

Change-Id: I30f0c61d478e9b405379e3bdfa512ed21a401a82
Revert "repopick: let's be nice to our servers :)"

This reverts commit d90c6dcb029ae803e155d2a35d08e7555f12163f.

Conflicts:
	tools/repopick.py

Change-Id: Ib1da7fa65eecd4835edc44249aab7306ab384a82