Upgrade flutter_lints in project template pubspec.yaml files (#172400)

The version of flutter_lints used by newly created projects should match
the version used by flutter_tools. This ensures that "pub get --offline"
will work on a project that was generated by "flutter create".

Also restore the Mac tool_tests_commands that were temporarily disabled
in https://github.com/flutter/flutter/pull/172388

Fixes https://github.com/flutter/flutter/issues/172375
https://dart.googlesource.com/external/github.com/flutter/flutter/+/99b69feacaa31cfa7a45c3446bda13497ed1c9fa

DEPS

diff --git a/DEPS b/DEPS
index 8b70333..0fe20ce 100644
--- a/DEPS
+++ b/DEPS
@@ -231,7 +231,7 @@
 deps = {
   'flutter/engine/src/flutter/third_party/dart': Var('dart_git') + '/sdk' + '@' + '8124814de564db8a026c66ac4c0c378df97a432b',
 
-  'flutter': Var('flutter_git') + '/mirrors/flutter' + '@' + '7b99061e06a88c8a412cedbcbba27a6933c3036e',
+  'flutter': Var('flutter_git') + '/mirrors/flutter' + '@' + '99b69feacaa31cfa7a45c3446bda13497ed1c9fa',
 
   'flutter/engine/src/flutter/third_party/depot_tools':
   Var('chromium_git') + '/chromium/tools/depot_tools.git' + '@' + '580b4ff3f5cd0dcaa2eacda28cefe0f45320e8f7',

commits.json

diff --git a/commits.json b/commits.json
index 3eba0d3..7ad6244 100644
--- a/commits.json
+++ b/commits.json
@@ -1,4 +1,4 @@
 {
-  "flutter":"7b99061e06a88c8a412cedbcbba27a6933c3036e",
+  "flutter":"99b69feacaa31cfa7a45c3446bda13497ed1c9fa",
   "flutter/engine/src/flutter/third_party/dart":"8124814de564db8a026c66ac4c0c378df97a432b"
 }
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