[feature] recognition of aliased mainactivities in manifest for debugging

[demonlol]

An app I'm working with uses 2 mainactivity references, one being encapsulated by < activity-alias > instead of < activity > in its manifest. As a result, a messagebox will appear stating "Failed to decode AndroidManifest.xml" upon clicking "Launch App". There are no stacktraces or logs.

I've added detection for it since then, but figured I'd follow repo guidelines before submitting a PR.

[skylot]

@demonlol this issue only appear while using debugger, right? Anyway, if possible, share sample APK.
And sure, PR with a fix will be great 👍

[demonlol]

@skylot That's right. It's an error in the debugger. As you requested, I've attached a sample APK which will produce the same results. Let me know if my modifications are unsatisfactory #1323
sample.zip

[skylot]

Fixed in PR #1323