hy_AM: Add alternative month names (bug 23140).

This locale already contained correct data in mon array.  Updated from
CLDR to start the month names with the lowercase letters.

alt_mon is a new import from CLDR.  The change has been consulted
off-list with a native speaker.

	[BZ #23140]
	* localedata/locales/hy_AM (mon): Synchronize with CLDR (lowercase,
	genitive case).
	(alt_mon): New entry, import from CLDR (nominative case).