Build - ota_from_target_files: Validate signatures after possible data wipe

If the data is being wiped, we want to validate the signature after
this step. This is also a good check that the data wipe succeeded.

Change-Id: I8a989374ba70ff570773701877d28621f87480c4
Signed-off-by: STELIX <ssspinni@gmail.com>
Build - ota: Fix recovery-script cleanups in block mode

Change-Id: Idcd6d183d4d587163ea9898381b74cb14d88e085
Signed-off-by: STELIX <ssspinni@gmail.com>