enable lints prefer_spread_collections and prefer_inlined_adds (#35189)

diff --git a/dev/bots/analyze-sample-code.dart b/dev/bots/analyze-sample-code.dart
index f26fc54..e07905f 100644
--- a/dev/bots/analyze-sample-code.dart
+++ b/dev/bots/analyze-sample-code.dart

@@ -286,13 +286,14 @@
           '--snapshot=$_snippetsSnapshotPath',
           '--snapshot-kind=app-jit',
           path.canonicalize(_snippetsExecutable),
-        ]..addAll(args),
+          ...args,
+        ],
         workingDirectory: workingDirectory,
       );
     } else {
       return Process.runSync(
         _dartExecutable,
-        <String>[path.canonicalize(_snippetsSnapshotPath)]..addAll(args),
+        <String>[path.canonicalize(_snippetsSnapshotPath), ...args],
         workingDirectory: workingDirectory,
       );
     }
@@ -311,7 +312,8 @@
     final List<String> args = <String>[
       '--output=${outputFile.absolute.path}',
       '--input=${inputFile.absolute.path}',
-    ]..addAll(snippet.args);
+      ...snippet.args,
+    ];
     print('Generating snippet for ${snippet.start?.filename}:${snippet.start?.line}');
     final ProcessResult process = _runSnippetsScript(args);
     if (process.exitCode != 0) {
@@ -854,9 +856,11 @@
         ),
       );
     }
-    return Section(<Line>[Line(prefix)]
-      ..addAll(codeLines)
-      ..add(Line(postfix)));
+    return Section(<Line>[
+      Line(prefix),
+      ...codeLines,
+      Line(postfix),
+    ]);
   }
   Line get start => code.firstWhere((Line line) => line.filename != null);
   final List<Line> code;
@@ -868,8 +872,8 @@
 /// analyzed.
 class Snippet {
   Snippet({this.start, List<String> input, List<String> args, this.serial}) {
-    this.input = <String>[]..addAll(input);
-    this.args = <String>[]..addAll(args);
+    this.input = input.toList();
+    this.args = args.toList();
   }
   final Line start;
   final int serial;

diff --git a/dev/bots/analyze.dart b/dev/bots/analyze.dart
index ffa96e2..4397e65 100644
--- a/dev/bots/analyze.dart
+++ b/dev/bots/analyze.dart

@@ -260,7 +260,9 @@
 Future<void> _runFlutterAnalyze(String workingDirectory, {
   List<String> options = const <String>[],
 }) {
-  return runCommand(flutter, <String>['analyze', '--dartdocs']..addAll(options),
+  return runCommand(
+    flutter,
+    <String>['analyze', '--dartdocs', ...options],
     workingDirectory: workingDirectory,
   );
 }
@@ -456,7 +458,10 @@
     final List<T> result = _deepSearch<T>(
       map,
       key,
-      (seen == null ? <T>{start} : Set<T>.from(seen))..add(key),
+      <T>{
+        if (seen == null) start else ...seen,
+        key,
+      },
     );
     if (result != null) {
       result.insert(0, start);

diff --git a/dev/bots/prepare_package.dart b/dev/bots/prepare_package.dart
index cd49939..d36eaf2 100644
--- a/dev/bots/prepare_package.dart
+++ b/dev/bots/prepare_package.dart

@@ -381,14 +381,14 @@
 
   Future<String> _runFlutter(List<String> args, {Directory workingDirectory}) {
     return _processRunner.runProcess(
-      <String>[_flutter]..addAll(args),
+      <String>[_flutter, ...args],
       workingDirectory: workingDirectory ?? flutterRoot,
     );
   }
 
   Future<String> _runGit(List<String> args, {Directory workingDirectory}) {
     return _processRunner.runProcess(
-      <String>['git']..addAll(args),
+      <String>['git', ...args],
       workingDirectory: workingDirectory ?? flutterRoot,
     );
   }
@@ -574,14 +574,14 @@
   }) async {
     if (platform.isWindows) {
       return _processRunner.runProcess(
-        <String>['python', path.join(platform.environment['DEPOT_TOOLS'], 'gsutil.py'), '--']..addAll(args),
+        <String>['python', path.join(platform.environment['DEPOT_TOOLS'], 'gsutil.py'), '--', ...args],
         workingDirectory: workingDirectory,
         failOk: failOk,
       );
     }
 
     return _processRunner.runProcess(
-      <String>['gsutil.py', '--']..addAll(args),
+      <String>['gsutil.py', '--', ...args],
       workingDirectory: workingDirectory,
       failOk: failOk,
     );

diff --git a/dev/bots/pubspec.yaml b/dev/bots/pubspec.yaml
index 21dacf8..865e3ff 100644
--- a/dev/bots/pubspec.yaml
+++ b/dev/bots/pubspec.yaml

@@ -3,7 +3,7 @@
 
 environment:
   # The pub client defaults to an <2.0.0 sdk constraint which we need to explicitly overwrite.
-  sdk: ">=2.2.0 <3.0.0"
+  sdk: ">=2.2.2 <3.0.0"
 
 dependencies:
   path: 1.6.2

diff --git a/dev/bots/test.dart b/dev/bots/test.dart
index 8efc6ca..e164800 100644
--- a/dev/bots/test.dart
+++ b/dev/bots/test.dart

@@ -220,7 +220,7 @@
     final List<String> testGroup = tests[i];
     await runCommand(
       dart,
-      <String>[path.join('tool', 'tool_coverage.dart'), '--']..addAll(testGroup),
+      <String>[path.join('tool', 'tool_coverage.dart'), '--', ...testGroup],
       workingDirectory: toolRoot,
       environment: <String, String>{
         'FLUTTER_ROOT': flutterRoot,
@@ -791,7 +791,7 @@
   Map<String, String> environment,
   List<String> tests = const <String>[],
 }) async {
-  final List<String> args = <String>['test']..addAll(options);
+  final List<String> args = <String>['test', ...options];
   if (flutterTestArgs != null && flutterTestArgs.isNotEmpty)
     args.addAll(flutterTestArgs);
 

diff --git a/dev/bots/test/fake_process_manager.dart b/dev/bots/test/fake_process_manager.dart
index 6a4136c..29f3cda 100644
--- a/dev/bots/test/fake_process_manager.dart
+++ b/dev/bots/test/fake_process_manager.dart

@@ -35,8 +35,7 @@
   set fakeResults(Map<String, List<ProcessResult>> value) {
     _fakeResults = <String, List<ProcessResult>>{};
     for (String key in value.keys) {
-      _fakeResults[key] = <ProcessResult>[]
-        ..addAll(value[key] ?? <ProcessResult>[ProcessResult(0, 0, '', '')]);
+      _fakeResults[key] = (value[key] ?? <ProcessResult>[ProcessResult(0, 0, '', '')]).toList();
     }
   }
 

diff --git a/dev/bots/unpublish_package.dart b/dev/bots/unpublish_package.dart
index cd09719..a91ce39 100644
--- a/dev/bots/unpublish_package.dart
+++ b/dev/bots/unpublish_package.dart

@@ -334,7 +334,7 @@
     bool failOk = false,
     bool confirm = false,
   }) async {
-    final List<String> command = <String>['gsutil', '--']..addAll(args);
+    final List<String> command = <String>['gsutil', '--', ...args];
     if (confirm) {
       return _processRunner.runProcess(
         command,
@@ -358,7 +358,7 @@
         print('  $file');
       }
     }
-    await _runGsUtil(<String>['rm']..addAll(files), failOk: true, confirm: confirmed);
+    await _runGsUtil(<String>['rm', ...files], failOk: true, confirm: confirmed);
   }
 
   Future<String> _cloudReplaceDest(String src, String dest) async {