Mask passwords included without quotes at the ends of commands

The current password masking doesn't scrub passwords from commands
in the case where the password doesn't have quotes around it and
the password is the last string in the command.  This commit updates
one of the regular expressions to catch this case.

Adds tests to ensure passwords at the ends of commands are properly
sanitized.

Change-Id: Id57a0cb05cd76ef8c26def738305ade6b085aaa7
Closes-Bug: #1320028
Merge "Mask passwords included without quotes at the ends of commands"