some whitespace cleanup (#14443)

diff --git a/packages/flutter_tools/lib/src/android/android_sdk.dart b/packages/flutter_tools/lib/src/android/android_sdk.dart
index 5b178b7..a024d73 100644
--- a/packages/flutter_tools/lib/src/android/android_sdk.dart
+++ b/packages/flutter_tools/lib/src/android/android_sdk.dart
@@ -168,7 +168,7 @@
       return null;
     }
 
-    // Try to find the NDK compiler.  If we can't find it, it's also ok.
+    // Try to find the NDK compiler. If we can't find it, it's also ok.
     final String ndkDir = findNdk(androidHomeDir);
     String ndkCompiler;
     List<String> ndkCompilerArgs;