[release/10.0] Don't set security descriptor if the mutex is not owned/new

[github-actions]

Backport of #120075 to release/10.0

/cc @ericstj @jozkee

Customer Impact

• Customer reported
• Found internally

Customer may hit an UnauthorizedAccessException when using Performance Counter or EventLog APIs. This happens when another user has created the Global\netfxperf.1.0 or Global\netfxeventlog.1.0 mutexes. This exception is impossible to predict and will be persistent when hit. The result is the opposite of the intent of the original fix. #110399

it is possible that security descriptor has an ACL for a particular account or group that is not compatible with a caller later on causing an access denied scenario.

Fix by only setting the ACL when we create the mutex.

Regression

• Yes
• No

Regression in .NET 10.0 from #110416

Testing

Manual repro and fix.

Risk

Low, we're just applying a condition to only set the ACL on a Mutex when we are the creator of that mutex.