[Question] Upgrade Gradle version

[zimml]

[READ] For Firebase Unity SDK question, please report to Firebase Unity Sample

Once you've read this section and determined that your issue is appropriate for this repository, please delete this section.

[REQUIRED] Please fill in the following fields:

• Pre-built SDK from the website or open-source from this repo: (https://firebase.google.com/download/cpp)
• Firebase C++ SDK version: 8.8.0
• Main Firebase Components in concern: General
• Other Firebase Components in use: General
• Platform you are using the C++ SDK on: Windows/Linux
• Platform you are targeting: Android

[REQUIRED] Please describe the question here:

Hi,

I'm using Firebase Cpp SDK for an hybrid application that targets Android / iOS / Windows / MacOS. For the Android version I notified that Firebase is still using Gradle 3.3.3. Is there some plane to update it to a newer version ? I ask that because with version < 4.1.0 we don't get any native debug symbols which would be of a great help to analyse crash occuring.

[google-oss-bot]

I couldn't figure out how to label this issue, so I've labeled it for a human to triage. Hang tight.

[a-maurice]

Hi, there isn't currently a plan to update the version, but that it is blocking native debug symbols is a good reason for it. I'll switch this issue into a feature request, to track it.

[jonsimantov]

We updated our Gradle version to 5.6.4 in #924.

Unfortunately, updating to 6.x or higher will involve fixing some breaking changes, so we have no plans to do so in the near future.