ANDROID: Add a build config fragment for KHWASan.

Bug: 182998770
Bug: 171327997
Bug: 170327170
Change-Id: I20db6a698b4d995f94bd592023a2a0b08b1f9548
Signed-off-by: Peter Collingbourne <pcc@google.com>

build.config.khwasan

@@ -0,0 +1,17 @@
+append_cmd POST_DEFCONFIG_CMDS update_khwasan_config
+
+function update_khwasan_config() {
+  ${KERNEL_DIR}/scripts/config --file ${OUT_DIR}/.config \
+    -e CONFIG_KASAN \
+    -d CONFIG_KASAN_HW_TAGS \
+    -e CONFIG_KASAN_SW_TAGS \
+    -e CONFIG_KASAN_OUTLINE \
+    -e CONFIG_KASAN_PANIC_ON_WARN \
+    -e CONFIG_KCOV \
+    -e CONFIG_PANIC_ON_WARN_DEFAULT_ENABLE \
+    -d CONFIG_RANDOMIZE_BASE \
+    --set-val CONFIG_FRAME_WARN 0 \
+    -d SHADOW_CALL_STACK
+  (cd ${OUT_DIR} && \
+   make O=${OUT_DIR} "${TOOL_ARGS[@]}" ${MAKE_ARGS} olddefconfig)
+}