jenkins: leaf-build: Delete prebuilt boot/recovery images before signing

* Otherwise prebuilts get picked up directly without any re-signing

Change-Id: I1b917c39d60d45176404ea3fe01dd4043d656c44
diff --git a/jenkins/leaf-build.sh b/jenkins/leaf-build.sh
index 9830302..9c4ee5f 100755
--- a/jenkins/leaf-build.sh
+++ b/jenkins/leaf-build.sh
@@ -99,6 +99,7 @@
 	[ "$TARGET_IS_GSI" ] && ALLOW_GSI_DEBUG_SEPOLICY="--allow_gsi_debug_sepolicy"
 	mkdir -p "/var/lib/jenkins/leaf/target-files/$RELEASE_DIR$JENKINS_DEVICE"
 	for JENKINS_FLAVOR in "${LEAF_FLAVORS[@]}"; do
+		zip -d "out/$JENKINS_DEVICE-target_files-$JENKINS_FLAVOR-$BUILD_ID.zip" "BOOTABLE_IMAGES/*" "IMAGES/*boot.img" "IMAGES/recovery.img"
 		"$OTATOOLS/sign_target_files_apks" -o -d "$KEY_DIR" \
 			$ALLOW_GSI_DEBUG_SEPOLICY \
 			--avb_vbmeta_key "$KEY_DIR/avb.pem" \