Adding fastboot-info version to host tool

Replacing check with PLATFORM_TOOLS_VERSION with FASTBOOT_INFO_VERSION
to indicate waht version of fastboot_info.txt we currently support. This
makes mor sense since PLATFORM_TOOLS_VERSION won't be updated every time
me make a change to the host tool

Test: fastboot flashall
Bug: 194686221
Change-Id: I621b62c92ba129f402857463dae9112a0797ab07