无法通过Android上传到Google Cloud Bucket

KeyStore keystore = KeyStore.getInstance("PKCS12");

keystore.load(r.openRawResource(R.raw.key),
        "password".toCharArray());

PrivateKey key = (PrivateKey) keystore.getKey("privatekey", "password".toCharArray());

GoogleCredential credential = new GoogleCredential.Builder().setTransport(httpTransport)
        .setJsonFactory(JSON_FACTORY)
        .setServiceAccountId(SERVICE_ACCOUNT_EMAIL)
        .setServiceAccountScopes(Collections.singleton(STORAGE_SCOPE))
        .setServiceAccountPrivateKey(key)
        //.setServiceAccountPrivateKeyFromP12File(new File("/storage/sdcard0/key.p12"))

        .build();
KeyStore keystore = KeyStore.getInstance("PKCS1