(FACT-3442) Update os.architecture fact for debian to arm64

Author: shubhamshinde360

acceptance/lib/facter/acceptance/base_fact_utils.rb

@@ -81,7 +81,7 @@ def debian_expected_facts(agent)
           os_hardware = 'x86_64'
           processor_model_pattern = /(Intel\(R\).*)|(AMD.*)/
         elsif agent['platform'] =~ /aarch64/
-          os_arch     = 'aarch64'
+          os_arch     = 'arm64'
           os_hardware = 'aarch64'
           processor_model_pattern = // # FACT-3439 - facter doesn't figure out the processor type on these machines 
         else