Android Ads - Content-Type parameter is not being sent in oAuth call

[tarasklimenko]

Description:

Currently the Content-Type parameter is NOT being sent in the oAuth call for the Android Ads SDK.

With BlackFlag Release 3.6.2, check for the content-type parameter is enforced causing a 415 - Unsupported Media Type error to be thrown

Expected:

Content-Type parameter to be sent in the oAuth call with the following value: Content-Type=application/x-www-form-urlencoded