Fixing AutomaticKeepAlive Docs (#48575)

packages/flutter/lib/src/widgets/scroll_view.dart

@@ -733,10 +733,10 @@ abstract class BoxScrollView extends ScrollView {
 ///    widget subtree with other widgets.
 ///
 ///  * Using [AutomaticKeepAlive] widgets (inserted by default when
-///    [addAutomaticKeepAlives] is true). Instead of unconditionally caching the
-///    child element subtree when scrolling off-screen like [KeepAlive],
-///    [AutomaticKeepAlive] can let whether to cache the subtree be determined
-///    by descendant logic in the subtree.
+///    [addAutomaticKeepAlives] is true). [AutomaticKeepAlive] allows descendant
+///    widgets to control whether the subtree is actually kept alive or not.
+///    This behavior is in contrast with [KeepAlive], which will unconditionally keep
+///    the subtree alive.
 ///
 ///    As an example, the [EditableText] widget signals its list child element
 ///    subtree to stay alive while its text field has input focus. If it doesn't

packages/flutter/lib/src/widgets/sliver.dart

@@ -91,10 +91,10 @@ int _kDefaultSemanticIndexCallback(Widget _, int localIndex) => localIndex;
 ///    `addRepaintBoundaries`.
 ///
 ///  * Using [AutomaticKeepAlive] widgets (inserted by default in
-///    [SliverChildListDelegate] or [SliverChildListDelegate]). Instead of
-///    unconditionally caching the child element subtree when scrolling
-///    off-screen like [KeepAlive], [AutomaticKeepAlive] can let whether to
-///    cache the subtree be determined by descendant logic in the subtree.
+///    [SliverChildListDelegate] or [SliverChildListDelegate]).
+///    [AutomaticKeepAlive] allows descendant widgets to control whether the
+///    subtree is actually kept alive or not. This behavior is in contrast with
+///    [KeepAlive], which will unconditionally keep the subtree alive.
 ///
 ///    As an example, the [EditableText] widget signals its sliver child element
 ///    subtree to stay alive while its text field has input focus. If it doesn't