Fix logic statements in year2023 documentation (flutter#174120)

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If year2023 (old specification) is true, then the indicator doesn't have
stop and gap. Not the other way around.

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Author: xVemu

packages/flutter/lib/src/material/progress_indicator.dart

@@ -381,7 +381,7 @@ class LinearProgressIndicator extends ProgressIndicator {
 
   /// The color of the stop indicator.
   ///
-  /// If [year2023] is false or [ThemeData.useMaterial3] is false, then no stop
+  /// If [year2023] is true or [ThemeData.useMaterial3] is false, then no stop
   /// indicator will be drawn.
   ///
   /// If null, then the [ProgressIndicatorThemeData.stopIndicatorColor] will be used.
@@ -390,7 +390,7 @@ class LinearProgressIndicator extends ProgressIndicator {
 
   /// The radius of the stop indicator.
   ///
-  /// If [year2023] is false or [ThemeData.useMaterial3] is false, then no stop
+  /// If [year2023] is true or [ThemeData.useMaterial3] is false, then no stop
   /// indicator will be drawn.
   ///
   /// Set [stopIndicatorRadius] to 0 to hide the stop indicator.
@@ -401,7 +401,7 @@ class LinearProgressIndicator extends ProgressIndicator {
 
   /// The gap between the indicator and the track.
   ///
-  /// If [year2023] is false or [ThemeData.useMaterial3] is false, then no track
+  /// If [year2023] is true or [ThemeData.useMaterial3] is false, then no track
   /// gap will be drawn.
   ///
   /// Set [trackGap] to 0 to hide the track gap.
@@ -811,7 +811,7 @@ class CircularProgressIndicator extends ProgressIndicator {
 
   /// The gap between the active indicator and the background track.
   ///
-  /// If [year2023] is false or [ThemeData.useMaterial3] is false, then no track
+  /// If [year2023] is true or [ThemeData.useMaterial3] is false, then no track
   /// gap will be drawn.
   ///
   /// Set [trackGap] to 0 to hide the track gap.

packages/flutter/lib/src/material/progress_indicator_theme.dart

@@ -86,13 +86,13 @@ class ProgressIndicatorThemeData with Diagnosticable {
 
   /// Overrides the stop indicator color of the [LinearProgressIndicator].
   ///
-  /// If [LinearProgressIndicator.year2023] is false or [ThemeData.useMaterial3]
+  /// If [LinearProgressIndicator.year2023] is true or [ThemeData.useMaterial3]
   /// is false, then no stop indicator will be drawn.
   final Color? stopIndicatorColor;
 
   /// Overrides the stop indicator radius of the [LinearProgressIndicator].
   ///
-  /// If [LinearProgressIndicator.year2023] is false or [ThemeData.useMaterial3]
+  /// If [LinearProgressIndicator.year2023] is true or [ThemeData.useMaterial3]
   /// is false, then no stop indicator will be drawn.
   final double? stopIndicatorRadius;
 
@@ -110,10 +110,10 @@ class ProgressIndicatorThemeData with Diagnosticable {
 
   /// Overrides the active indicator and the background track.
   ///
-  /// If [CircularProgressIndicator.year2023] is false or [ThemeData.useMaterial3]
+  /// If [CircularProgressIndicator.year2023] is true or [ThemeData.useMaterial3]
   /// is false, then no track gap will be drawn.
   ///
-  /// If [LinearProgressIndicator.year2023] is false or [ThemeData.useMaterial3]
+  /// If [LinearProgressIndicator.year2023] is true or [ThemeData.useMaterial3]
   /// is false, then no track gap will be drawn.
   final double? trackGap;
 

packages/flutter/lib/src/material/slider_theme.dart

@@ -631,7 +631,7 @@ class SliderThemeData with Diagnosticable {
   /// The Slider defaults to [GappedSliderTrackShape] when the track shape is
   /// not specified, and the [trackGap] can be used to adjust the gap size.
   ///
-  /// If [Slider.year2023] is false or [ThemeData.useMaterial3] is false, then
+  /// If [Slider.year2023] is true or [ThemeData.useMaterial3] is false, then
   /// the Slider track shape defaults to [RoundedRectSliderTrackShape] and the
   /// [trackGap] is ignored. In this case, set the track shape to
   /// [GappedSliderTrackShape] to use the [trackGap].