base

Fix some typos and other cosmetic cleanups in telephony framework.

- Fix typos in Javadoc and comments.
- Fix Javadoc @link references to other classes/methods.
- Rename MISSING_UKNOWN_APN to MISSING_UNKNOWN_APN in DataConnection.
- Remove unused (and misspelled) RETRYIES_* consts in RetryManager.

Change-Id: I3b44ac8320d6c1e4c350be600c7ef266aaf735e4