fyne android build - arm32 and arm64 build in one step

[bytemystery-com]

Checklist

• I have searched the issue tracker for open issues that relate to the same feature, before opening a new one.
• This issue only relates to a single feature. I will open new issues for any other features.

Is your feature request related to a problem?

No

Is it possible to construct a solution with the existing API?

No

Describe the solution you'd like to see.

I would like to build arm32 and arm64 support inan apk or aab file
fyne package -os android builds all inclusive x86 stuff which is not really needed (except emulator)
so
fyne package -target android/arm,android/arm64 would be nice