build: configure binary-compatibility-validator

Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>

build.gradle.kts

@@ -4,14 +4,18 @@
  */
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 import com.android.build.gradle.BaseExtension
+import kotlinx.validation.ApiValidationExtension
 
 buildscript {
     repositories {
         google()
         jcenter()
+        // For binary compatibility validator.
+        maven { url = uri("https://kotlin.bintray.com/kotlinx") }
     }
     dependencies {
         classpath(Plugins.agp)
+        classpath(Plugins.binaryCompatibilityValidator)
         classpath(Plugins.kotlin)
     }
 }
@@ -20,6 +24,14 @@ plugins {
     id("com.github.ben-manes.versions") version "0.31.0"
 }
 
+apply(plugin = "binary-compatibility-validator")
+
+extensions.configure<ApiValidationExtension> {
+  ignoredProjects = mutableSetOf(
+      "app"
+  )
+}
+
 subprojects {
     repositories {
         google()

buildSrc/src/main/java/Dependencies.kt

@@ -8,6 +8,7 @@ private const val KOTLIN_VERSION = "1.4.10"
 object Plugins {
 
     const val agp = "com.android.tools.build:gradle:4.0.1"
+    const val binaryCompatibilityValidator = "org.jetbrains.kotlinx:binary-compatibility-validator:0.2.3"
     const val kotlin = "org.jetbrains.kotlin:kotlin-gradle-plugin:$KOTLIN_VERSION"
 }