Make the BA a string while creating a challenge for WP payment

[SathyaJayabal]

Make the BA a string while creating a challenge for WP payment
https://topcoder.slack.com/archives/C01T50SRHDE/p1621338405002000
cc @nkumar-topcoder

[nkumar-topcoder]

@sandhiyakavi @SathyaJayabal This is fixed in DEV. please check.

cc @maxceem

[sandhiyakavi]

@nkumar-topcoder @maxceem Currently I am getting "Billing account is not assigned to the resource booking" error with 409 conflict status eventhough billing account is assigned to the Resource Booking . Hence not able to create Work period payments for the same.

Sample: https://platform.topcoder-dev.com/taas/myteams/17340/rb/81dbce93-1167-4bff-8125-de8ad0d34778
BillingAccountId added to RB: 80000068
WP : 1669110d-be05-4ca6-8e38-9a9b64081942

[sandhiyakavi]

Verified on Dev.

![Uploading image.png…]()

[SathyaJayabal]

verified on prod.