node-builder: multiple runtime_make_flags text lines

Concatenate multiple strings into runtime_make_flags, to make
package_build.sh easier to read.

Signed-off-by: Dan Mihai <dmihai@microsoft.com>

Author: danmihai1

tools/osbuilder/node-builder/azure-linux/package_build.sh

@@ -20,8 +20,9 @@ common_file="common.sh"
 source "${common_file}"
 
 # these options ensure we produce the proper CLH config file
-runtime_make_flags="SKIP_GO_VERSION_CHECK=1 QEMUCMD= FCCMD= ACRNCMD= STRATOVIRTCMD= DEFAULT_HYPERVISOR=cloud-hypervisor
-	DEFMEMSZ=0 DEFSTATICSANDBOXWORKLOADMEM=512 DEFVCPUS=0 DEFSTATICSANDBOXWORKLOADVCPUS=1 DEFVIRTIOFSDAEMON=${VIRTIOFSD_BINARY_LOCATION} PREFIX=${INSTALL_PATH_PREFIX}"
+runtime_make_flags="SKIP_GO_VERSION_CHECK=1 QEMUCMD= FCCMD= ACRNCMD= STRATOVIRTCMD= DEFAULT_HYPERVISOR=cloud-hypervisor"
+runtime_make_flags+=" DEFMEMSZ=0 DEFSTATICSANDBOXWORKLOADMEM=512 DEFVCPUS=0 DEFSTATICSANDBOXWORKLOADVCPUS=1"
+runtime_make_flags+=" DEFVIRTIOFSDAEMON=${VIRTIOFSD_BINARY_LOCATION} PREFIX=${INSTALL_PATH_PREFIX}"
 
 # - for vanilla Kata we use the kernel binary. For ConfPods we use IGVM, so no need to provide kernel path.
 # - for vanilla Kata we explicitly set DEFSTATICRESOURCEMGMT_CLH. For ConfPods,