ota: Generate recovery-from-boot.p file

This may be wanted to update the recovery with system updates

Change-Id: Iacd41be7a8018cbc08b2606485d446756910f506
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
Merge tag 'android-4.4.3_r1' into HEAD

Android 4.4.3 release 1

Change-Id: Ie4ad0f5e2785df0f5083e1bc93951ce389b293e5
Merge tag 'android-4.4.3_r1.1' into HEAD

Android 4.4.3 release 1.1

Change-Id: I814a785dd9e199c1d1168fea761a20ddc897904a