Merge pull request #236 from android/jv/fix-warnings-as-errors

Use GradleLocalProperties for reading warningsAsErrors

.github/ci-gradle.properties

@@ -21,5 +21,8 @@ org.gradle.workers.max=2
 kotlin.incremental=false
 kotlin.compiler.execution.strategy=in-process
 
-# Controls KotlinOptions.allWarningsAsErrors. This is used in CI and can be set in local properties.
-warningsAsErrors=true
+# Controls KotlinOptions.allWarningsAsErrors.
+# This value used in CI and is currently set to false.
+# If you want to treat warnings as errors locally, set this property to true
+# in your ~/.gradle/gradle.properties file.
+warningsAsErrors=false

build-logic/convention/src/main/kotlin/com/google/samples/apps/nowinandroid/KotlinAndroid.kt

@@ -23,6 +23,7 @@ import org.gradle.api.artifacts.VersionCatalogsExtension
 import org.gradle.api.plugins.ExtensionAware
 import org.gradle.kotlin.dsl.dependencies
 import org.gradle.kotlin.dsl.getByType
+import org.gradle.kotlin.dsl.provideDelegate
 import org.jetbrains.kotlin.gradle.dsl.KotlinJvmOptions
 
 /**
@@ -46,7 +47,9 @@ internal fun Project.configureKotlinAndroid(
 
         kotlinOptions {
             // Treat all Kotlin warnings as errors (disabled by default)
-            allWarningsAsErrors = properties["warningsAsErrors"] as? Boolean ?: false
+            // Override by setting warningsAsErrors=true in your ~/.gradle/gradle.properties
+            val warningsAsErrors: String? by project
+            allWarningsAsErrors = warningsAsErrors.toBoolean()
 
             freeCompilerArgs = freeCompilerArgs + listOf(
                 "-opt-in=kotlin.RequiresOptIn",