Rename update_device.py's --disable-vabc param

update_device.py has a --disable-vabc option, and what it really does is
set virtual ab compression param to none, but still uses snapuserd.
There is also a --disable-vabc option in ota_from_target_files, which
completely disables virtual ab compression and fall back to plain vab.
To keep naming consistent, rename update_device.py's option to
--vabc-none.

Test: th
Change-Id: Ifba27f19ed8132bf1a3023481740461faa50207c
diff --git a/common/constants.h b/common/constants.h
index 36c4476..dc45e72 100644
--- a/common/constants.h
+++ b/common/constants.h
@@ -178,7 +178,7 @@
 
 // Set Virtual AB Compression's compression algorithm to "none", but still use
 // userspace snapshots and snapuserd for update installation.
-static constexpr const auto& kPayloadDisableVABC = "DISABLE_VABC";
+static constexpr const auto& kPayloadVABCNone = "VABC_NONE";
 // Enable multi-threaded compression for VABC
 static constexpr const auto& kPayloadEnableThreading = "ENABLE_THREADING";
 // Enable batched writes for VABC