restructured the add to app samples (#698)

add_to_app/fullscreen/ios_fullscreen/Podfile.lock

@@ -0,0 +1,35 @@
+PODS:
+  - espresso (0.0.1):
+    - Flutter
+  - Flutter (1.0.0)
+  - flutter_module (0.0.1):
+    - Flutter
+  - FlutterPluginRegistrant (0.0.1):
+    - espresso
+    - Flutter
+
+DEPENDENCIES:
+  - espresso (from `../flutter_module/.ios/Flutter/.symlinks/espresso/ios`)
+  - Flutter (from `../flutter_module/.ios/Flutter/engine`)
+  - flutter_module (from `../flutter_module/.ios/Flutter`)
+  - FlutterPluginRegistrant (from `../flutter_module/.ios/Flutter/FlutterPluginRegistrant`)
+
+EXTERNAL SOURCES:
+  espresso:
+    :path: "../flutter_module/.ios/Flutter/.symlinks/espresso/ios"
+  Flutter:
+    :path: "../flutter_module/.ios/Flutter/engine"
+  flutter_module:
+    :path: "../flutter_module/.ios/Flutter"
+  FlutterPluginRegistrant:
+    :path: "../flutter_module/.ios/Flutter/FlutterPluginRegistrant"
+
+SPEC CHECKSUMS:
+  espresso: f754d95a407073c29489b0d82c4119de517b3f2f
+  Flutter: 0e3d915762c693b495b44d77113d4970485de6ec
+  flutter_module: d1e1ff44505640bd9aa37f23f63380c646272be4
+  FlutterPluginRegistrant: 1a0bd13c92b7db07c180b8d2f1eb5749b7cf1b6d
+
+PODFILE CHECKSUM: 1f9809794b37c933b7cb40791d64724dc2376c54
+
+COCOAPODS: 1.8.4