Enable R8 (#40453)

diff --git a/packages/flutter_tools/lib/src/build_info.dart b/packages/flutter_tools/lib/src/build_info.dart
index c406438..57ee601 100644
--- a/packages/flutter_tools/lib/src/build_info.dart
+++ b/packages/flutter_tools/lib/src/build_info.dart
@@ -92,7 +92,7 @@
       AndroidArch.arm64_v8a,
     ],
     this.splitPerAbi = false,
-    this.proguard = false,
+    this.shrink = false,
   });
 
   // The build info containing the mode and flavor.
@@ -105,8 +105,8 @@
   /// will be produced.
   final bool splitPerAbi;
 
-  /// Whether to enable Proguard on release mode.
-  final bool proguard;
+  /// Whether to enable code shrinking on release mode.
+  final bool shrink;
 
   /// The target platforms for the build.
   final Iterable<AndroidArch> targetArchs;