Media type not supported in cognitoidentityprovider

[nterbogt]

I'm running into an issue with UpdateManagedLoginBranding in cognitoidentityprovider service.

My code works as expected with settings, user pool id, etc. But when adding assets it runs into the follow error.

InvalidParameterException: Invalid assets provided. Validation errors: [{category: PAGE_BACKGROUND, extension: SVG, colorMode: DYNAMIC, errorMessage: "Media type not supported for value: text/plain"}]

The (pseudo) code in question is

awstypes "github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider/types"

awstypes.AssetType{
    Category:    awstypes.AssetCategoryTypePageBackground,
    ColorMode: awstypes.ColorSchemeModeTypeDynamic,
    Bytes:          []byte("PHN2Zz48L3N2Zz4="),  // '<svg></svg>'|base64
    Extension:   awstypes.AssetExtensionTypeSvg,
}

But to confirm I also ran the following with no issues.

awstypes "github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider/types"

var empty []byte
awstypes.AssetType{
    Category:    awstypes.AssetCategoryTypePageBackground,
    ColorMode: awstypes.ColorSchemeModeTypeDynamic,
    Bytes:          empty
    Extension:   awstypes.AssetExtensionTypeSvg,
}

I suspect there is an issue in type conversion of Byte for the http request.

There are people experiencing similar issues with the aws cli and I just want to confirm if there is something I'm doing wrong or if there is actually an underlying issue.

aws/aws-cli#9102