Set plugin template minimum iOS version to 12.0 (#143167)

Fixes https://github.com/flutter/flutter/issues/140474

See https://github.com/flutter/flutter/pull/122625 where this was done 11->12.

dev/devicelab/lib/tasks/plugin_tests.dart

@@ -429,7 +429,7 @@ end
       throw TaskResult.failure('podspec file missing at ${podspec.path}');
     }
     final String versionString = target == 'ios'
-        ? "s.platform = :ios, '11.0'"
+        ? "s.platform = :ios, '12.0'"
         : "s.platform = :osx, '10.11'";
     String podspecContent = podspec.readAsStringSync();
     if (!podspecContent.contains(versionString)) {

packages/flutter_tools/templates/plugin/ios-objc.tmpl/projectName.podspec.tmpl

@@ -16,7 +16,7 @@ Pod::Spec.new do |s|
   s.source_files = 'Classes/**/*'
   s.public_header_files = 'Classes/**/*.h'
   s.dependency 'Flutter'
-  s.platform = :ios, '11.0'
+  s.platform = :ios, '12.0'
 
   # Flutter.framework does not contain a i386 slice.
   s.pod_target_xcconfig = { 'DEFINES_MODULE' => 'YES', 'EXCLUDED_ARCHS[sdk=iphonesimulator*]' => 'i386' }

packages/flutter_tools/templates/plugin/ios-swift.tmpl/projectName.podspec.tmpl

@@ -15,7 +15,7 @@ Pod::Spec.new do |s|
   s.source           = { :path => '.' }
   s.source_files = 'Classes/**/*'
   s.dependency 'Flutter'
-  s.platform = :ios, '11.0'
+  s.platform = :ios, '12.0'
 
   # Flutter.framework does not contain a i386 slice.
   s.pod_target_xcconfig = { 'DEFINES_MODULE' => 'YES', 'EXCLUDED_ARCHS[sdk=iphonesimulator*]' => 'i386' }

packages/flutter_tools/templates/plugin_ffi/ios.tmpl/projectName.podspec.tmpl

@@ -20,7 +20,7 @@ Pod::Spec.new do |s|
   s.source           = { :path => '.' }
   s.source_files = 'Classes/**/*'
   s.dependency 'Flutter'
-  s.platform = :ios, '11.0'
+  s.platform = :ios, '12.0'
 
   # Flutter.framework does not contain a i386 slice.
   s.pod_target_xcconfig = { 'DEFINES_MODULE' => 'YES', 'EXCLUDED_ARCHS[sdk=iphonesimulator*]' => 'i386' }

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

@@ -2849,7 +2849,7 @@ void main() {
     expect(env['flutter']!.allows(Version(3, 2, 9)), false);
   });
 
-  testUsingContext('newly created iOS plugins has min iOS version of 11.0', () async {
+  testUsingContext('newly created iOS plugins has correct min iOS version', () async {
     Cache.flutterRoot = '../..';
     final String flutterToolsAbsolutePath = globals.fs.path.join(
       Cache.flutterRoot!,
@@ -2882,7 +2882,7 @@ void main() {
 
     for (final String templatePath in iosPluginTemplates) {
       final String rawTemplate = globals.fs.file(templatePath).readAsStringSync();
-      expect(rawTemplate, contains("s.platform = :ios, '11.0'"));
+      expect(rawTemplate, contains("s.platform = :ios, '12.0'"));
     }
 
     final CreateCommand command = CreateCommand();
@@ -2892,7 +2892,7 @@ void main() {
     expect(projectDir.childDirectory('ios').childFile('flutter_project.podspec'),
         exists);
     final String rawPodSpec = await projectDir.childDirectory('ios').childFile('flutter_project.podspec').readAsString();
-    expect(rawPodSpec, contains("s.platform = :ios, '11.0'"));
+    expect(rawPodSpec, contains("s.platform = :ios, '12.0'"));
   });
 
   testUsingContext('default app uses flutter default versions', () async {

packages/integration_test/ios/integration_test.podspec

@@ -20,6 +20,6 @@ LICENSE
   s.dependency 'Flutter'
   s.ios.framework  = 'UIKit'
 
-  s.platform = :ios, '11.0'
+  s.platform = :ios, '12.0'
   s.pod_target_xcconfig = { 'DEFINES_MODULE' => 'YES', 'EXCLUDED_ARCHS[sdk=iphonesimulator*]' => 'i386' }
 end