Use of Configuration APKs while still targeting pre lollipop devices

Question

When developing for Instant Apps the use of Configuration APKs (https://developer.android.com/topic/instant-apps/guides/config-splits.html) offers useful option for cutting

Answer 1

Since the minSdkVersion flag will toggle quite a few checks, this change is not done automatically for you.

I'd recommend introducing a product flavor for both the installed and instant module with different minSdkVersions, like this:

// :feature/base/build.gradle

flavorDimensions 'delivery'

productFlavors {
    instant {
        dimension 'delivery'
        minSdkVersion rootProject.minSdkInstant
    }
    installed {
        dimension 'delivery'
    }
}

This will have to be done similarly in other modules that depend on the feature module with API level < 21.

Answer 2

Instant apps are only supported in API 21+ devices (link), older devices will only support full apk.

The better approach is to define different minSdk based on your module, like:

You can take a look at Google's analytics sample on GitHub

Project's gradle

ext {
    buildTools = '26.0.2'
    compileSdk = 26
    minSdk = 15
    minSdkInstant = 21
    versionCode = 1
    versionName = '1.0'
    supportLib = '26.1.0'
    firebaseVer = '10.2.4'
    instantAppsVer = '1.0.0'
}

Base gradle

android {
    compileSdkVersion rootProject.compileSdk
    buildToolsVersion rootProject.buildTools
    baseFeature true
    defaultConfig {
        minSdkVersion rootProject.minSdk
        targetSdkVersion rootProject.compileSdk
        versionCode rootProject.versionCode
        versionName rootProject.versionName
    }
    buildTypes {
        release {}
    }
}

Installed gradle

 defaultConfig {
        applicationId "com.example.android.instant.analytics"
        minSdkVersion rootProject.minSdk
        targetSdkVersion rootProject.compileSdk
        versionCode rootProject.versionCode
        versionName rootProject.versionName

    }

Instant gradle

android {
    defaultConfig {
        minSdkVersion rootProject.minSdkInstant
    }
}

Answer 3

You can specify a different lower minSdkVersion for your application module if you use tools:overrideLibrary Please see How do I use tools:overrideLibrary in a build.gradle file?

This is how I did it:

app/build.gradle

android {
    defaultConfig {
        minSdkVersion 17
    }
}

app’s manifest

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.package.app" xmlns:tools="http://schemas.android.com/tools" >

    <uses-sdk tools:overrideLibrary="com.package,com.package.feature"/>

</manifest>

You will need to add all the package names where you wish to override their minSdkVersion. You will know which ones to add by looking at the error:

Manifest merger failed ... AndroidManifest.xml as the library might be using APIs not available in 17 Suggestion: use a compatible library with a minSdk of at most 17, or increase this project's minSdk version to at least 21, or use tools:overrideLibrary="com.package.feature" to force usage (may lead to runtime failures)

base and feature/build.gradle

android {
    defaultConfig {
        minSdkVersion 21
    }
}

Test it by building the installed/instant APKs, then analyzing then for the minSdkVersion value. The installed should be at 17, and your base/feature APKs will still be on 21.