Fix use of deprecated buildDir in Android templates/tests/examples (#157560)

Replace deprecated `Project.buildDir` [getter](https://docs.gradle.org/current/javadoc/org/gradle/api/Project.html#getBuildDir()) and [setter](https://docs.gradle.org/current/javadoc/org/gradle/api/Project.html#setBuildDir(java.io.File)) uses.

dev/benchmarks/macrobenchmarks/android/build.gradle

@@ -13,10 +13,12 @@ allprojects {
     }
 }
 
-rootProject.buildDir = '../build'
+Directory newBuildDir = rootProject.layout.buildDirectory.dir("../../build").get()
+rootProject.layout.buildDirectory.value(newBuildDir)
 
 subprojects {
-    project.buildDir = "${rootProject.buildDir}/${project.name}"
+    def newSubprojectBuildDir = newBuildDir.dir(project.name)
+    project.layout.buildDirectory.value(newSubprojectBuildDir)
 }
 subprojects {
     project.evaluationDependsOn(':app')
@@ -30,5 +32,5 @@ subprojects {
 }
 
 tasks.register("clean", Delete) {
-    delete rootProject.buildDir
+    delete rootProject.layout.buildDirectory
 }

dev/benchmarks/microbenchmarks/android/build.gradle

@@ -9,10 +9,10 @@ allprojects {
     }
 }
 
-rootProject.buildDir = '../build'
+rootProject.layout.buildDirectory.value(rootProject.layout.buildDirectory.dir("../../build").get())
 
 subprojects {
-    project.buildDir = "${rootProject.buildDir}/${project.name}"
+    project.layout.buildDirectory.value(rootProject.layout.buildDirectory.dir(project.name).get())
 }
 subprojects {
     project.evaluationDependsOn(':app')
@@ -25,5 +25,5 @@ subprojects {
 }
 
 tasks.register("clean", Delete) {
-    delete rootProject.buildDir
+    delete rootProject.layout.buildDirectory
 }

dev/benchmarks/multiple_flutters/android/build.gradle

@@ -26,5 +26,5 @@ allprojects {
 }
 
 tasks.register("clean", Delete) {
-    delete rootProject.buildDir
+    delete rootProject.layout.buildDirectory
 }

dev/integration_tests/deferred_components_test/android/build.gradle

@@ -34,10 +34,10 @@ project.getTasks().withType(JavaCompile){
     options.compilerArgs << "-Xlint:all" << "-Werror"
 }
 
-rootProject.buildDir = '../build'
+rootProject.layout.buildDirectory.value(rootProject.layout.buildDirectory.dir("../../build").get())
 
 subprojects {
-    project.buildDir = "${rootProject.buildDir}/${project.name}"
+    project.layout.buildDirectory.value(rootProject.layout.buildDirectory.dir(project.name).get())
     project.evaluationDependsOn(':app')
 
     dependencyLocking {
@@ -50,5 +50,5 @@ subprojects {
 }
 
 tasks.register("clean", Delete) {
-    delete rootProject.buildDir
+    delete rootProject.layout.buildDirectory
 }

dev/integration_tests/deferred_components_test/android/component1/build.gradle

@@ -28,8 +28,8 @@ android {
 
     sourceSets {
         applicationVariants.all { variant ->
-            main.assets.srcDirs += "${project.buildDir}/intermediates/flutter/${variant.name}/deferred_assets"
-            main.jniLibs.srcDirs += "${project.buildDir}/intermediates/flutter/${variant.name}/deferred_libs"
+            main.assets.srcDirs += "${project.layout.buildDirectory.get()}/intermediates/flutter/${variant.name}/deferred_assets"
+            main.jniLibs.srcDirs += "${project.layout.buildDirectory.get()}/intermediates/flutter/${variant.name}/deferred_libs"
         }
     }
 

dev/integration_tests/gradle_deprecated_settings/android/build.gradle

@@ -29,10 +29,10 @@ allprojects {
     }
 }
 
-rootProject.buildDir = '../build'
+rootProject.layout.buildDirectory.value(rootProject.layout.buildDirectory.dir("../../build").get())
 
 subprojects {
-    project.buildDir = "${rootProject.buildDir}/${project.name}"
+    project.layout.buildDirectory.value(rootProject.layout.buildDirectory.dir(project.name).get())
 }
 subprojects {
     project.evaluationDependsOn(':app')
@@ -46,5 +46,5 @@ subprojects {
 }
 
 tasks.register("clean", Delete) {
-    delete rootProject.buildDir
+    delete rootProject.layout.buildDirectory
 }

dev/integration_tests/module_host_with_custom_build_v2_embedding/build.gradle

@@ -20,5 +20,5 @@ allprojects {
 }
 
 tasks.register("clean", Delete) {
-    delete rootProject.buildDir
+    delete rootProject.layout.buildDirectory
 }

dev/integration_tests/native_driver_test/android/build.gradle

@@ -9,14 +9,14 @@ allprojects {
     }
 }
 
-rootProject.buildDir = "../build"
+rootProject.layout.buildDirectory.value(rootProject.layout.buildDirectory.dir("../../build").get())
 subprojects {
-    project.buildDir = "${rootProject.buildDir}/${project.name}"
+    project.layout.buildDirectory.value(rootProject.layout.buildDirectory.dir(project.name).get())
 }
 subprojects {
     project.evaluationDependsOn(":app")
 }
 
 tasks.register("clean", Delete) {
-    delete rootProject.buildDir
+    delete rootProject.layout.buildDirectory
 }

dev/tools/bin/generate_gradle_lockfiles.dart

@@ -237,10 +237,10 @@ allprojects {
     }
 }
 
-rootProject.buildDir = '../build'
+rootProject.layout.buildDirectory.value(rootProject.layout.buildDirectory.dir("../../build").get())
 
 subprojects {
-    project.buildDir = "${rootProject.buildDir}/${project.name}"
+    project.layout.buildDirectory.value(rootProject.layout.buildDirectory.dir(project.name).get())
 }
 subprojects {
     project.evaluationDependsOn(':app')
@@ -254,7 +254,7 @@ subprojects {
 }
 
 tasks.register("clean", Delete) {
-    delete rootProject.buildDir
+    delete rootProject.layout.buildDirectory
 }
 ''';
 

dev/tracing_tests/android/build.gradle

@@ -9,14 +9,14 @@ allprojects {
     }
 }
 
-rootProject.buildDir = '../build'
+rootProject.layout.buildDirectory.value(rootProject.layout.buildDirectory.dir("../../build").get())
 subprojects {
-    project.buildDir = "${rootProject.buildDir}/${project.name}"
+    project.layout.buildDirectory.value(rootProject.layout.buildDirectory.dir(project.name).get())
 }
 subprojects {
     project.evaluationDependsOn(':app')
 }
 
 tasks.register("clean", Delete) {
-    delete rootProject.buildDir
+    delete rootProject.layout.buildDirectory
 }