[flutter_tools] retry sever socket setup (and port selection if port is unspecified) (#69351)

Fixes #69348

If the web development server fails to bind, then retry up to 5 times. If a port was not provided, select a new free port each time.

packages/flutter_tools/lib/src/isolated/resident_web_runner.dart

@@ -483,11 +483,6 @@ class _ResidentWebRunner extends ResidentWebRunner {
       'Launching ${globals.fsUtils.getDisplayPath(target)} '
       'on ${device.device.name} in $modeName mode...',
     );
-    final String effectiveHostname = debuggingOptions.hostname ?? 'localhost';
-    final int hostPort = debuggingOptions.port == null
-        ? await globals.os.findFreePort()
-        : int.tryParse(debuggingOptions.port);
-
     if (device.device is ChromiumDevice) {
       _chromiumLauncher = (device.device as ChromiumDevice).chromeLauncher;
     }
@@ -498,10 +493,11 @@ class _ResidentWebRunner extends ResidentWebRunner {
           debuggingOptions.webEnableExpressionEvaluation
               ? WebExpressionCompiler(device.generator)
               : null;
-
         device.devFS = WebDevFS(
-          hostname: effectiveHostname,
-          port: hostPort,
+          hostname: debuggingOptions.hostname ?? 'localhost',
+          port: debuggingOptions.port != null
+            ? int.tryParse(debuggingOptions.port)
+            : null,
           packagesFilePath: packagesFilePath,
           urlTunneller: urlTunneller,
           useSseForDebugProxy: debuggingOptions.webUseSseForDebugProxy,

packages/flutter_tools/test/general.shard/web/devfs_web_test.dart

@@ -699,7 +699,7 @@ void main() {
       contains('GENERATED'));
 
     // served on localhost
-    expect(uri, Uri.http('localhost:0', ''));
+    expect(uri.host, 'localhost');
 
     await webDevFS.destroy();
   }, overrides: <Type, Generator>{
@@ -813,7 +813,7 @@ void main() {
       contains('GENERATED'));
 
     // served on localhost
-    expect(uri, Uri.http('localhost:0', ''));
+    expect(uri.host, 'localhost');
 
     await webDevFS.destroy();
   }, overrides: <Type, Generator>{
@@ -859,7 +859,7 @@ void main() {
 
     final Uri uri = await webDevFS.create();
 
-    expect(uri, Uri.http('localhost:0', ''));
+    expect(uri.host, 'localhost');
     await webDevFS.destroy();
   }));