Add more tips for androidLicensesUnknown (#61312)

packages/flutter_tools/lib/src/base/user_messages.dart

@@ -96,9 +96,8 @@ class UserMessages {
   String get androidLicensesNone => 'Android licenses not accepted.  To resolve this, run: flutter doctor --android-licenses';
   String androidLicensesUnknown(Platform platform) =>
       'Android license status unknown.\n'
-      'Try re-installing or updating your Android SDK Manager.\n'
-      'See https://developer.android.com/studio/#downloads or visit '
-      '${_androidSdkInstallUrl(platform)} for detailed instructions.';
+      'Run `flutter doctor --android-licenses` to accept the SDK licenses.\n'
+      'See ${_androidSdkInstallUrl(platform)} for more details.';
   String androidSdkManagerOutdated(String managerPath) =>
       'A newer version of the Android SDK is required. To update, run:\n'
       '$managerPath --update\n';