In the spirit of TIMTOWTDI, I figured the record looked similar enough to a Perl data structure to warrant some gratuitous use regular expressions. So I came up with the following:

use strict;
use warnings;

# parse the follow text block (as given) - not trying
# to make a general solution here...

my $text = do { local $/; <DATA> };


$text =~ s/^(.+)\{/qw|$1|,\n\r{/;
$text =~ s/ \{/ => {/g;
$text =~ s/{(.+)}/\[qw\/$1\/\]/g;
$text =~ s/}/},/g;
$text =~ s/]/],/g;
$text =~ s/(\w+-\w+) =/'$1' =/g;
$text =~ s/ (\w+) "(.+)"/ $1 => "$2",/;

$text = sprintf qq{[%s]}, $text;
my $record1 = eval $text;

require Data::Dumper;
print Data::Dumper::Dumper($record1);


__DATA__
sys ecm cloud-provider /Common/aws-ec2 {
    description "The aws-ec2 parameters"
    property-template {
        account { }
        availability-zone {
            valid-values { a b c d }
        }
        instance-type {
            valid-values { t2.micro t2.small t2.medium }
        }
        region {
            valid-values { us-east-1 us-west-1 }
        }
    }
}
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Which outputs,

$VAR1 = [
          'sys',
          'ecm',
          'cloud-provider',
          '/Common/aws-ec2',
          {
            'property-template' => {
                                     'account' => [],
                                     'region' => {
                                                   'valid-values' => [
                                                                      
+ 'us-east-1',
                                                                      
+ 'us-west-1'
                                                                     ]
                                                 },
                                     'instance-type' => {
                                                          'valid-value
+s' => [
                                                                      
+        't2.micro',
                                                                      
+        't2.small',
                                                                      
+        't2.medium'
                                                                      
+      ]
                                                        },
                                     'availability-zone' => {
                                                              'valid-v
+alues' => [
                                                                      
+            'a',
                                                                      
+            'b',
                                                                      
+            'c',
                                                                      
+            'd'
                                                                      
+          ]
                                                            }
                                   },
            'description' => 'The aws-ec2 parameters'
          }
        ];
[download]