Revert "build: Export MK_BUILDTYPE to shell"

This reverts commit c736f48fe72877c89a90081cfc8a1710c827947a.
OTA: Avoid different major versions

Change-Id: Id04b11e341a3fef879c85f4e9ac149eea7313d27
Merge "OTA: Avoid different major versions" into kk_mkt