Please check that project is configured properly and your module has Android facet and Android SDK Platform in the dependencies.
IntelliJ IDEA performs indexing of the JSDK, Android Platform and your project when you open it for the first time. You need to wait for the indexing process to complete (progress is displayed in the status bar at the bottom).
Once indexing is complete, you should get all the code completion options available. If for some reason it still doesn't work, try File
| Invalidate Caches
and restart IDEA.