fix: Prevent appending uploadTask more than once

[bitsandfoxes]

Fixes #2195, #2170

Problem

I still fail to reproduce this on both macOS and Windows. But given that the issue is appending the upload task multiple times there are only two places where this could fail:

1. The check whether the upload task is there is insufficient

   sentry-unity/src/Sentry.Unity.Editor/Android/DebugSymbolUpload.cs

   Line 185 in dbbb63c

   if (!gradleBuildFile.Contains("sentry.properties"))

2. Removing the task is failing

   sentry-unity/src/Sentry.Unity.Editor/Android/DebugSymbolUpload.cs

   Lines 191 to 192 in dbbb63c

   	var regex = new Regex(Regex.Escape(SymbolUploadTaskStartComment) + ".*" + Regex.Escape(SymbolUploadTaskEndComment), RegexOptions.Singleline);
   	gradleBuildFile = regex.Replace(gradleBuildFile, "");

   • A possible explanation the I can see is that the SDK fails to remove the entirety of the upload task. During the following build it fails to recognize the task already exists and erroneously appends another one.

Proposal

The SDK is needs to be more defensive about adding the upload task to the Gradle file and prevent duplicated appending.

1. Check for the actual marker instead of the .properties
2. Update the regex to non-greedy handle multiply added upload tasks. The SDK fails to properly remove the entire task due to regex.Replace not doing what we expect it to do?
3. Add a sanity check before adding the task with proper logging how to unblock yourself

[bitsandfoxes]

Unrelated but: To reduce logging noise when the SDK is disabled.

[bitsandfoxes]

This now happens outside and before calling this method. Added a sanity check before actually writing to disk.

[bitsandfoxes]

@sentry review

[seer-by-sentry]

🔒 GenAI Consent Required

To enable PR review and test generation via Prevent, an organization admin needs to:

1. Go to your Sentry organization settings
2. Enable GenAI features for your organization
3. Enable the PR Review and Test Generation toggle

Once enabled, you can re-trigger this review by commenting.

[bitsandfoxes]

bugbot review

Addressed the concern raised in regards to the regex being off.