build.config.gki_kasan was not setting the correct configs to disable
LTO for KASAN builds, since the configs differ between when LTO support
was first created downstream vs what landed upstream.

These builds are large and take a long time to build with LTO added.

CONFIG_LTO and CONFIG_LTO_CLANG are not user selectable. Instead, set
LTO=none which build.sh will interpret then properly disable
CONFIG_LTO_CLANG_FULL, CONFIG_LTO_CLANG_THIN, and enable
CONFIG_LTO_NONE.

Bug: 225394140
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Change-Id: I79d1ea94b04d0a55afeb8df2874aeb7099bb030c