Adjust plugins and packages .gitignore to be most useful (#88991)

* Update .gitignore.tmpl

* Add pubspec.lock

* Exclude example/pubspec.lock

* Address feedback

packages/flutter_tools/templates/package/.gitignore.tmpl

@@ -21,55 +21,9 @@
 #.vscode/
 
 # Flutter/Dart/Pub related
+# Libraries should not include pubspec.lock, per https://dart.dev/guides/libraries/private-files#pubspeclock.
+/pubspec.lock
 **/doc/api/
 .dart_tool/
-.flutter-plugins
-.flutter-plugins-dependencies
 .packages
-.pub-cache/
-.pub/
 build/
-
-# Android related
-**/android/**/gradle-wrapper.jar
-**/android/.gradle
-**/android/captures/
-**/android/gradlew
-**/android/gradlew.bat
-**/android/local.properties
-**/android/**/GeneratedPluginRegistrant.java
-
-# iOS/XCode related
-**/ios/**/*.mode1v3
-**/ios/**/*.mode2v3
-**/ios/**/*.moved-aside
-**/ios/**/*.pbxuser
-**/ios/**/*.perspectivev3
-**/ios/**/*sync/
-**/ios/**/.sconsign.dblite
-**/ios/**/.tags*
-**/ios/**/.vagrant/
-**/ios/**/DerivedData/
-**/ios/**/Icon?
-**/ios/**/Pods/
-**/ios/**/.symlinks/
-**/ios/**/profile
-**/ios/**/xcuserdata
-**/ios/.generated/
-**/ios/Flutter/App.framework
-**/ios/Flutter/Flutter.framework
-**/ios/Flutter/Flutter.podspec
-**/ios/Flutter/Generated.xcconfig
-**/ios/Flutter/ephemeral
-**/ios/Flutter/app.flx
-**/ios/Flutter/app.zip
-**/ios/Flutter/flutter_assets/
-**/ios/Flutter/flutter_export_environment.sh
-**/ios/ServiceDefinitions.json
-**/ios/Runner/GeneratedPluginRegistrant.*
-
-# Exceptions to above rules.
-!**/ios/**/default.mode1v3
-!**/ios/**/default.mode2v3
-!**/ios/**/default.pbxuser
-!**/ios/**/default.perspectivev3

packages/flutter_tools/templates/plugin/.gitignore.tmpl

+# Miscellaneous
+*.class
+*.log
+*.pyc
+*.swp
 .DS_Store
-.dart_tool/
+.atom/
+.buildlog/
+.history
+.svn/
 
-.packages
-.pub/
+# IntelliJ related
+*.iml
+*.ipr
+*.iws
+.idea/
+
+# The .vscode folder contains launch configuration and tasks you configure in
+# VS Code which you may wish to be included in version control, so this line
+# is commented out by default.
+#.vscode/
 
+# Flutter/Dart/Pub related
+# Libraries should not include pubspec.lock, per https://dart.dev/guides/libraries/private-files#pubspeclock.
+/pubspec.lock
+**/doc/api/
+.dart_tool/
+.packages
 build/