Thanks to _that, return null if vector is empty

Change-Id: Idc44455dd0c971c876ae283528c4367a82e145bd
Clean up make flash utility make files

Change-Id: Ie396be7d9636a8b481bcf7c062f94ce51a4b1fde
Make libmincrypttwrp a shared library

Change-Id: I8c3f084fc34b00edb4cd1b652290df8bc80ea1db