Fix heat-container-agent image building error on arm64

Fix bellow building error on arm64.
----------
  build/temp.linux-aarch64-3.8/_openssl.c:498:10: fatal error: openssl/opensslv.h: No such file or directory
    498 | #include <openssl/opensslv.h>
        |          ^~~~~~~~~~~~~~~~~~~~
  compilation terminated.
  error: command 'gcc' failed with exit status 1
  ----------------------------------------
  ERROR: Failed building wheel for cryptography
  Running setup.py clean for cryptography
  Failed to build cryptography
  ERROR: Could not build wheels for cryptography
  which use PEP 517 and cannot be installed directly
----------

Additionally, add an ARCH ARG to pass other architecure value when
building image.
E.g: $ docker build --build-arg ARCH=`uname -m` -t TAGNAME .

task: 37823
story: 2007026

Change-Id: I7f62b882fa812beb74e38bbc5916d9df5afbd481

dockerfiles/heat-container-agent/Dockerfile

@@ -1,5 +1,7 @@
 FROM fedora:rawhide
 
+ARG ARCH=x86_64
+
 # Fill out the labels
 LABEL name="heat-container-agent" \
       maintainer="Spyros Trigazis <strigazi@gmail.com>" \
@@ -7,7 +9,7 @@ LABEL name="heat-container-agent" \
       summary="Heat Container Agent system image" \
       version="1.0" \
       help="No help" \
-      architecture="x86_64" \
+      architecture=$ARCH \
       atomic.type="system" \
       distribution-scope="public"
 
@@ -19,6 +21,7 @@ RUN dnf -y --setopt=tsflags=nodocs --nogpgcheck install \
         libffi-devel \
         openssh-clients \
         openssl \
+        openssl-devel \
         python-devel \
         python-lxml \
         python-pip \