fix: Enable multidex support for versions older than API 21

[vtrifonov]

As with the latest version of the graddle we've enabled multidex by default we need to handle multidex processing in API levels older than api 21.
Fixes #999

[ns-bot]

💚

[Burgov]

I'm getting this error now, do i need to do anything?

Could not resolve all files for configuration ':app:debugCompileClasspath'.
> Could not find any version that matches com.android.support:multidex:26.0.+.
  Versions that do not match:
      1.0.1
      1.0.0
      1.0.3
      1.0.2

[darind]

@Burgov can you show your project.json and also if you made some changes to app/App_Resources/app.gradle so that we try to reproduce the error?

[Burgov]

@darind thanks for your quick response and for pointing me in the right direction.

To fix an earlier issue, I had this in my app.gradle:

dependencies {
    configurations.all {
        resolutionStrategy.eachDependency { DependencyResolveDetails details ->
            def requested = details.requested
            if (requested.group == 'com.android.support') {
                details.useVersion '26.0.+'
            }
        }
    }
}

Changing it to look like what's in this post: https://stackoverflow.com/a/45025597/1001966 fixes it.