Enable side-by-side beta and dev channels.

chrome/test/mini_installer/config/chrome_canary_not_installed.prop

 {
-  "Condition": "$SUPPORTS_SXS",
+  "Condition": "'$BRAND' == 'Google Chrome'",
   "Files": {
     "$LOCAL_APPDATA\\$CHROME_DIR_SXS\\Application": {
       "exists": false
     }
   },
   "RegistryEntries": {
     "HKEY_CURRENT_USER\\$CHROME_UPDATE_REGISTRY_SUBKEY_SXS": {
       "exists": "forbidden"
     },
     "HKEY_CURRENT_USER\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall\\$CHROME_LONG_NAME_SXS": {
       "exists": "forbidden"
     },
     "HKEY_CURRENT_USER\\Software\\Classes\\$CHROME_SHORT_NAME_SXS$USER_SPECIFIC_REGISTRY_SUFFIX": {
       "exists": "forbidden"
     }
   }
 }