Trim recipient addresses that are unreasonably long.

This ensures that bad input does not affect the db - the fallback is a reasonable one where we just launch the new conversation screen and have the user select the recipient.

TESTED=manually confirmed that I could no longer repro b/278556945 after this change.
BUG=278556945

Change-Id: I705a304a92cb46b20d916c6f5c2db81e6fa84f06