Fixes / Changes roadmap

[drcabral]

applied some changes / fixes suggested in #25

• Included “file formats” section in Android Studio Layer
• Changed Notifications section to “also nice to know” block
• In “user interface” section:
  • Created data views section and moved adapter view, spinner and recycler view (with the observation about listview and gridview) to there
  • Moved fragments section to here
• Fixed smoke tests typo
• Volley removed from “network handling” section and added "Data Transfer Format" with REST, GraphQL, Protocol Buffer and FlatBuffer
• Removed Android X box
• Added R8 in security section
• Added a note in “Animation” section about “Animated Vector Drawables”