Remove EXPAND/STRINGIFY macros.

This reverts commit 8be0f39f to reland
the change that removes EXPAND/STRINGIFY macros.

It's error-prone by putting anything into a string (e.g.
EXPAND(RECOVERY_API_VERSION) would become "RECOVER_API_VERSION" if we
forgot to pass -DRECOVERY_API_VERSION=3).

The initial attempt put RECOVERY_API_VERSION into common.h, which might
be included by device-specific codes but without defining that when
compiling the module. This CL avoids the issue by using a constant
in the header, with a static_assert in recovery.cpp that guards the
consistency.

Test: recovery_component_test
Test: Sideload OTAs on bullhead and sailfish respectively.
Change-Id: I12af3f73392a85554ba703f04970ec9d984ccbaa