Generate android version code accounting for arch and min sdk

[OptimusGREEN]

Android version code is generated to account for the architecture it is built for as well as the minimum sdk.

The new version format is arch-minsdk-app version

This will allow apps of the same version name built for different architectures be uploaded to the play store and will provide separation for overlap.

example:
app version: 1.0.5
min sdk: 21

old style version code would be 10005 for all architectures

new version codes would be:
x86: 62110005
arm7: 72110005
arm8: 82110005

[inclement]

Nice, thanks.

[j-devel]

@OptimusGREEN I just found that apk build for x86_64 is failing:

  File "/home/a/.local/share/python-for-android/dists/unnamed_dist_1/build.py", line 368, in make_package
    arch_code = arch_dict[arch]
KeyError: u'x86_64'

Will x86_64 case be supported? 🤔

[OptimusGREEN]

Hmmm, I wasn't aware that x86_64 was supported as Buildozer spec only offers the other 3 as arch options. The Android arch to build for, choices: armeabi-v7a, arm64-v8a, x86 @inclement we could always add this in if supported?

[inclement]

@OptimusGREEN Go ahead, updating the buildozer.spec would be welcome. Thanks!

[OptimusGREEN]

updated this to include x86_64 here #1733 and also spec here kivy/buildozer#839