Sync eng/common directory with azure-sdk-tools for PR 7630 (#22349)

* Add ContentType header to Update-GitHubIssue

* replaced application/json

* Update eng/common/scripts/Invoke-GitHubAPI.ps1

Co-authored-by: Daniel Jurek <djurek@microsoft.com>

---------

Co-authored-by: Peng Jiahui <804873052@qq.com>
Co-authored-by: Wes Haggard <weshaggard@users.noreply.github.com>
Co-authored-by: Daniel Jurek <djurek@microsoft.com>

eng/common/scripts/Invoke-GitHubAPI.ps1

@@ -402,7 +402,8 @@ function Update-GitHubIssue {
           -Body ($parameters | ConvertTo-Json) `
           -Uri $uri `
           -Headers (Get-GitHubApiHeaders -token $AuthToken) `
-          -MaximumRetryCount 3
+          -MaximumRetryCount 3 `
+          -ContentType "application/json"
 }
 
 function Remove-GitHubSourceReferences  {