Fix using universal apk when abi-splits are present

[jarl-balling]

Before: plugin failed to use universalApk if abi-splits were also present.
Now: if abi-splits are present then look for universalApk before throwing error.

Fixes issue #2

[Malinskiy]

Hey. Thanks for submitting this
Curious if there is a better way to check for universal apk as an API instead of relying on file name substring?

[jarl-balling]

Hey. Thanks for submitting this Curious if there is a better way to check for universal apk as an API instead of relying on file name substring?

Howdy! For now all I have is this:

When building multiple APKs, Gradle generates APK filenames using the following scheme: modulename-screendensityABI-buildvariant.apk
If universalApk is enabled for per-ABI APKs, Gradle uses universal as the ABI portion of the universal APK filename.
Source: https://developer.android.com/build/configure-apk-splits?hl=en#build-apks-filename

Now that I think about it the proposed change might lead to a different error down the line for apps with moduleName/apkName akin to myUniversalApp-x86abi-developmentDebug.apk. I'll look into it, maybe there is a better way to do it.

[jarl-balling]

Turns out we can use VariantOutputConfiguration.OutputType to check for a valid .apk:

• VariantOutputConfiguration.OutputType.SINGLEwhen there are no splits
• VariantOutputConfiguration.OutputType.UNIVERSAL when there are splits but universalAPK is also present

I've tried it out and it seems to work fine. AGP also uses similar logic inside of BuiltArtifactsImpl class.