Restore device icons [3/n]

Summary: Restored support for device icons which was disabled in previous diff

Reviewed By: passy

Differential Revision: D31054802

fbshipit-source-id: 107a53f06159211534cb9a2316340af7a7ca530a

desktop/flipper-plugin/src/types/server-types.tsx

@@ -33,6 +33,7 @@ export type DeviceDescription = {
   readonly title: string;
   readonly deviceType: DeviceType;
   readonly serial: string;
+  readonly icon?: string;
   // Android specific information
   readonly specs?: DeviceSpec[];
   readonly abiList?: string[];