Revert "Put fuchsia tools into their own directory, and set source_dir to...

Revert "Put fuchsia tools into their own directory, and set source_dir to point at them. (#52266)" (#52277)

This reverts commit ffcc7765.

packages/flutter_tools/BUILD.gn

@@ -56,8 +56,7 @@ dart_library("flutter_tools") {
 }
 
 dart_tool("fuchsia_builder") {
-  main_dart = "bin/fuchsia/fuchsia_builder.dart"
-  source_dir = "bin/fuchsia"
+  main_dart = "bin/fuchsia_builder.dart"
 
   disable_analysis = true
 
@@ -67,8 +66,7 @@ dart_tool("fuchsia_builder") {
 }
 
 dart_tool("fuchsia_asset_builder") {
-  main_dart = "bin/fuchsia/fuchsia_asset_builder.dart"
-  source_dir = "bin/fuchsia"
+  main_dart = "bin/fuchsia_asset_builder.dart"
 
   disable_analysis = true
 
@@ -154,8 +152,7 @@ dart_tool("fuchsia_asset_builder") {
 }
 
 dart_tool("fuchsia_tester") {
-  main_dart = "bin/fuchsia/fuchsia_tester.dart"
-  source_dir = "bin/fuchsia"
+  main_dart = "bin/fuchsia_tester.dart"
 
   disable_analysis = true
 
@@ -250,8 +247,7 @@ dart_tool("fuchsia_tester") {
 
 dart_tool("fuchsia_attach") {
   package_name = "fuchsia_attach"
-  main_dart = "bin/fuchsia/fuchsia_attach.dart"
-  source_dir = "bin/fuchsia"
+  main_dart = "bin/fuchsia_attach.dart"
 
   # Can be left empty as analysis is disabled.
   sources = []