Squashed revert of TARGET_UNIFIED_DEVICE

* vendor init can be used to achieve everything done here

Revert "core: Fix unified trees with no TARGET_OTA_ASSERT_DEVICE"
This reverts commit e44fa493.

Revert "releasetools: don't attempt to read fingerprint on unified devices"
This reverts commit 787a0aa7.

Revert "buildinfo: only set ro.build.product on non-unified devices"
This reverts commit 22c034b8.

Revert "ota_from_target_files: Remove device dependent arguments"
This reverts commit 7c93b441.

Revert "Fix ro.build.product not found by ota_from_target_files in some cases"
This reverts commit 0ca54950.

Revert "Allow devices to specify certain ro. props via TARGET_UNIFIED_DEVICE"
This reverts commit 8182bc29.

ota_from_target_files: Remove device dependent arguments
These device-specific arguments are defined at build time and are
necessary to generate the zip correctly. Don't use command line
arguments to specify them, but write all the needed information
in misc_info.txt when the target-files zip is generated.
ota_from_target_files will then read misc_info.txt and set
everything automatically.
Original Change-Id: Ibdbca575b76eb07b53fccfcea52a351c7e333f91
[mikeioannina]: Reapply after TARGET_UNIFIED_DEVICE removal

Change-Id: I5cb8f074c893c0e46edf507f6256cd747239d07f