app/build.gradle

import groovy.xml.XmlUtil

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'

android {

    compileSdkVersion 28
    buildToolsVersion '28.0.3'

    defaultConfig {
        minSdkVersion 26
        targetSdkVersion 28
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
        }
    }

    lintOptions {
        abortOnError false
    }
    compileOptions {
        targetCompatibility 1.8
        sourceCompatibility 1.8
    }
    testOptions {
        unitTests.all {
            useJUnitPlatform()
            testLogging {
                events "passed", "skipped", "failed"
            }
        }
    }

    sourceSets {
        test {
            java.srcDirs += "$projectDir/src/sharedTest/java"
        }
        androidTest {
            java.srcDirs += "$projectDir/src/sharedTest/java"
        }
    }

    // optional signingConfigs
    def keystorePropertiesFile = rootProject.file("keystore.properties")
    if (keystorePropertiesFile.exists()) {
        def keystoreProperties = new Properties()
        keystoreProperties.load(new FileInputStream(keystorePropertiesFile))

        signingConfigs {
            release {
                keyAlias keystoreProperties['keyAlias']
                keyPassword keystoreProperties['keyPassword']
                storeFile file(keystoreProperties['storeFile'])
                storePassword keystoreProperties['storePassword']
            }
        }
        buildTypes.release.signingConfig = signingConfigs.release
        buildTypes.debug.signingConfig = signingConfigs.release
    }
}

gradle.projectsEvaluated {
    tasks.withType(JavaCompile) {
        options.compilerArgs.add('-Xbootclasspath/p:app/libs/android.jar:app/libs/libcore.jar')
    }
}

// http://www.31mins.com/android-studio-build-system-application/
preBuild.doLast {
    def imlFile = file(project.name + ".iml")

    try {
        def parsedXml = (new XmlParser()).parse(imlFile)
        def jdkNode = parsedXml.component[1].orderEntry.find { it.'@type' == 'jdk' }
        parsedXml.component[1].remove(jdkNode)

        def sdkString = "Android API " + android.compileSdkVersion.substring("android-".length()) + " Platform"
        new Node(parsedXml.component[1], 'orderEntry', ['type': 'jdk', 'jdkName': sdkString, 'jdkType': 'Android SDK'])
        XmlUtil.serialize(parsedXml, new FileOutputStream(imlFile))

    } catch (NullPointerException | FileNotFoundException ex) {
        ex.printStackTrace()
    }
}

// To produce these binaries, in latest AOSP source tree, run
// $ make
def aospDeps = fileTree(include: [
        // out/target/common/obj/JAVA_LIBRARIES/framework_intermediates/classes.jar
        'android.jar',
        // out/target/common/obj/JAVA_LIBRARIES/core-libart_intermediates/classes.jar
        'libcore.jar'
], dir: 'libs')

dependencies {
    compileOnly aospDeps

    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"

    implementation 'commons-io:commons-io:2.6'
    implementation 'io.github.novacrypto:BIP39:2019.01.27'

    implementation 'androidx.core:core-ktx:1.0.2'
    implementation 'androidx.preference:preference-ktx:1.0.0'
    implementation 'com.google.android.material:material:1.0.0'
    implementation 'androidx.lifecycle:lifecycle-extensions:2.0.0'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'

    lintChecks 'com.github.thirdegg:lint-rules:0.0.4-alpha'

    testImplementation aospDeps
    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.5.0'
    testImplementation 'io.mockk:mockk:1.9.3'
    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.5.0'

    androidTestImplementation 'androidx.test:runner:1.2.0'
    androidTestImplementation 'androidx.test:rules:1.2.0'
}