Add example IntelliJ metadata (flutter-intellij#607). (#7428)

* Add example IntelliJ metadata (flutter-intellij#607).

Ensures example projects open cleanly out-of-the-box w/ the Flutter Plugin.

See: https://github.com/flutter/flutter-intellij/issues/607.

* Fixed IML files.

examples/flutter_gallery/.idea/modules.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/flutter_gallery.iml" filepath="$PROJECT_DIR$/flutter_gallery.iml" />
+    </modules>
+  </component>
+</project>
\ No newline at end of file

examples/flutter_gallery/flutter_gallery.iml

@@ -9,7 +9,6 @@
       <excludeFolder url="file://$MODULE_DIR$/test/calculator/packages" />
       <excludeFolder url="file://$MODULE_DIR$/test/packages" />
     </content>
-    <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />
     <orderEntry type="library" name="Dart SDK" level="application" />
     <orderEntry type="library" name="Dart Packages" level="project" />

examples/hello_world/.idea/modules.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/hello_world.iml" filepath="$PROJECT_DIR$/hello_world.iml" />
+    </modules>
+  </component>
+</project>
\ No newline at end of file

examples/hello_world/.idea/runConfigurations/hello_world.xml

+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="hello_world" type="FlutterRunConfigurationType" factoryName="Flutter">
+    <option name="filePath" value="$PROJECT_DIR$/lib/main.dart" />
+    <method />
+  </configuration>
+</component>

examples/hello_world/hello_world.iml

@@ -8,7 +8,6 @@
       <excludeFolder url="file://$MODULE_DIR$/packages" />
       <excludeFolder url="file://$MODULE_DIR$/test/packages" />
     </content>
-    <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />
     <orderEntry type="library" name="Dart SDK" level="application" />
     <orderEntry type="library" name="Dart Packages" level="project" />

examples/layers/.idea/modules.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/layers.iml" filepath="$PROJECT_DIR$/layers.iml" />
+    </modules>
+  </component>
+</project>
\ No newline at end of file

examples/layers/layers.iml

+<?xml version="1.0" encoding="UTF-8"?>
+<module type="FLUTTER_MODULE_TYPE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <excludeFolder url="file://$MODULE_DIR$/.pub" />
+      <excludeFolder url="file://$MODULE_DIR$/build" />
+      <excludeFolder url="file://$MODULE_DIR$/packages" />
+      <excludeFolder url="file://$MODULE_DIR$/test/packages" />
+    </content>
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" name="Dart SDK" level="application" />
+    <orderEntry type="library" name="Dart Packages" level="project" />
+  </component>
+</module>
\ No newline at end of file

examples/stocks/.idea/modules.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/stocks.iml" filepath="$PROJECT_DIR$/stocks.iml" />
+    </modules>
+  </component>
+</project>
\ No newline at end of file

examples/stocks/.idea/runConfigurations/stocks.xml

+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="stocks" type="FlutterRunConfigurationType" factoryName="Flutter">
+    <option name="filePath" value="$PROJECT_DIR$/lib/main.dart" />
+    <method />
+  </configuration>
+</component>

examples/stocks/stocks.iml

+<?xml version="1.0" encoding="UTF-8"?>
+<module type="FLUTTER_MODULE_TYPE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <excludeFolder url="file://$MODULE_DIR$/.pub" />
+      <excludeFolder url="file://$MODULE_DIR$/build" />
+      <excludeFolder url="file://$MODULE_DIR$/packages" />
+      <excludeFolder url="file://$MODULE_DIR$/test/packages" />
+    </content>
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" name="Dart SDK" level="application" />
+    <orderEntry type="library" name="Dart Packages" level="project" />
+  </component>
+</module>
\ No newline at end of file