7.2-Preview to GA (Azure#13919)

* 7.2-Preview to GA

* Update packages to point to stable

* Readd exportable and update description

* Update description for exportable in preview versions

Author: jlichwa

specification/keyvault/data-plane/Microsoft.KeyVault/preview/7.1/keys.json

@@ -1295,7 +1295,7 @@
       "properties": {
         "exportable": {
           "type": "boolean",
-          "description": "Indicates if the private key can be exported."
+          "description": "Not supported in this version. Indicates if the private key can be exported."
         },
         "kty": {
           "x-ms-client-name": "keyType",

specification/keyvault/data-plane/Microsoft.KeyVault/preview/7.2-preview/keys.json

@@ -1298,6 +1298,10 @@
     },
     "KeyProperties": {
       "properties": {
+        "exportable": {
+          "type": "boolean",
+          "description": "Not supported in this version. Indicates if the private key can be exported."
+        },
         "kty": {
           "x-ms-client-name": "keyType",
           "type": "string",

specification/keyvault/data-plane/Microsoft.KeyVault/stable/7.1/keys.json

@@ -1295,7 +1295,7 @@
       "properties": {
         "exportable": {
           "type": "boolean",
-          "description": "Indicates if the private key can be exported."
+          "description": "Not supported in this version. Indicates if the private key can be exported."
         },
         "kty": {
           "x-ms-client-name": "keyType",