Remove conditionality in templates that was for AGP <= 4.2 support (flutter#151845)

Not needed after flutter#149204 (as long as nothing has changed since the comment was made �).

Fixes flutter#145105.

Author: gmackall

packages/flutter_tools/templates/module/android/gradle/build.gradle.tmpl

@@ -24,11 +24,7 @@ apply plugin: "com.android.library"
 apply plugin: "kotlin-android"
 
 android {
-    // Conditional for compatibility with AGP <4.2.
-    if (project.android.hasProperty("namespace")) {
-        namespace = "{{androidIdentifier}}"
-    }
-
+    namespace = "{{androidIdentifier}}"
     compileSdk = {{compileSdkVersion}}
     defaultConfig {
         minSdk = {{minSdkVersion}}

packages/flutter_tools/templates/module/android/host_app_common/app.tmpl/build.gradle.tmpl

@@ -3,11 +3,7 @@ def flutterPluginVersion = "managed"
 apply plugin: "com.android.application"
 
 android {
-    // Conditional for compatibility with AGP <4.2.
-    if (project.android.hasProperty("namespace")) {
-        namespace = "{{androidIdentifier}}.host"
-    }
-
+    namespace = "{{androidIdentifier}}.host"
     compileSdk = {{compileSdkVersion}}
 
     compileOptions {

packages/flutter_tools/templates/module/android/library_new_embedding/Flutter.tmpl/build.gradle.tmpl

@@ -30,11 +30,7 @@ group = "{{androidIdentifier}}"
 version = "1.0"
 
 android {
-    // Conditional for compatibility with AGP <4.2.
-    if (project.android.hasProperty("namespace")) {
-        namespace = "{{androidIdentifier}}"
-    }
-
+    namespace = "{{androidIdentifier}}"
     compileSdk = flutter.compileSdkVersion
     ndkVersion = flutter.ndkVersion
 

packages/flutter_tools/test/commands.shard/permeable/create_test.dart

@@ -3054,8 +3054,6 @@ void main() {
     final String buildGradleContent = await buildGradleFile.readAsString();
 
     expect(buildGradleContent.contains('namespace = "com.bar.foo.flutter_project"'), true);
-    // The namespace should be conditionalized for AGP <4.2.
-    expect(buildGradleContent.contains('if (project.android.hasProperty("namespace")) {'), true);
   });
 
   testUsingContext('Android FFI plugin contains namespace', () async {
@@ -3077,8 +3075,6 @@ void main() {
     final String buildGradleContent = await buildGradleFile.readAsString();
 
     expect(buildGradleContent.contains('namespace = "com.bar.foo.flutter_project"'), true);
-    // The namespace should be conditionalized for AGP <4.2.
-    expect(buildGradleContent.contains('if (project.android.hasProperty("namespace")) {'), true);
   });
 
   testUsingContext('Android Kotlin plugin contains namespace', () async {
@@ -3101,8 +3097,6 @@ void main() {
     final String buildGradleContent = await buildGradleFile.readAsString();
 
     expect(buildGradleContent.contains('namespace = "com.bar.foo.flutter_project"'), true);
-    // The namespace should be conditionalized for AGP <4.2.
-    expect(buildGradleContent.contains('if (project.android.hasProperty("namespace")) {'), true);
   });
 
   testUsingContext('Flutter module Android project contains namespace', () async {
@@ -3128,13 +3122,6 @@ void main() {
     expect(moduleFlutterBuildGradleFileContent.contains(expectedNameSpace), true);
     const String expectedHostNameSpace = 'namespace = "com.bar.foo.flutter_project.host"';
     expect(moduleAppBuildGradleFileContent.contains(expectedHostNameSpace), true);
-
-    // The namespaces should be conditionalized for AGP <4.2.
-    const String expectedConditional = 'if (project.android.hasProperty("namespace")) {';
-    expect(moduleBuildGradleFileContent.contains(expectedConditional), true);
-    expect(moduleAppBuildGradleFileContent.contains(expectedConditional), true);
-    expect(moduleFlutterBuildGradleFileContent.contains(expectedConditional), true);
-
   }, overrides: <Type, Generator>{
     Pub: () => Pub.test(
       fileSystem: globals.fs,