feat: Support customize output apk signing levels

[meolunr]

Feature description

Please refer to this PR: ReVanced/revanced-cli#329

Motivation

Some apps verify their own signatures. Checks for V2/V3/V4 signatures can be bypassed by patching the verification code, but some legacy apps validate the V1 signature by reading the APK file directly.

This feature adds support for custom signature levels, allowing the original V1 signature to be retained while only re-signing with V2/V3/V4. Since the Android system prioritizes higher-level signature verification, this change will not affect normal app installation.

Acknowledgements

• I have checked all open and closed feature requests and this is not a duplicate.
• I have chosen an appropriate title.

[prateek-who]

Yea, this is clearly an upgrade. Are there any catches here? If there aren't any then we can get into implementing this.

[meolunr]

Good! Simply preserve the original V1 signature (files under the META directory) when the V1 re-signing flag is not added to --signing-levels.

[prateek-who]

@LisoUseInAIKyrios For this feature, where do we put it in the gui? In the settings panel itself?

[LisoUseInAIKyrios]

Yes somewhere in the settings panel sounds ok if it's added to the GUI.

But this is a very specific use case. Does it need to be exposed in the GUI? It requires using it with specific patches and specific apps. Should this be CLI only?

[prateek-who]

That is also fine, we could keep this cli only. I was thinking we keep the gui and cli in harmony when it comes to features but then again, this is a very niche feature and if somebody was gonna use this, they would be an advanced users who is well versed with the cli. So let's keep this cli only then?