Merged PR 8965360: enable reduce image size for slim image build

enable reduce image size for slim image build
sonic-net#16729

Signed-off-by: xuliping <xuliping@microsoft.com>

Author: lipxu

.pipelines/OneBranch.OfficialBuild.yml

@@ -212,6 +212,7 @@ stages:
             echo "INCLUDE_KUBERNETES = y" >> rules/config.user
             echo "INCLUDE_MACSEC = n" >> rules/config.user
             echo "INCLUDE_P4RT = n" >> rules/config.user
+            echo "BUILD_REDUCE_IMAGE_SIZE = y" >> rules/config.user
             make $OPTIONS target/sonic-broadcom.bin target/sonic-aboot-broadcom.swi
             mv target/sonic-broadcom.bin target/sonic-broadcom-slim.bin
             mv target/sonic-aboot-broadcom.swi target/sonic-aboot-broadcom-slim.swi