Added equals() and hashCode() to ArrayMap to allow equals() tests
of maps with the same key/value pairs to return true.
Changed putAll() to handle the case of an empty map faster, just copying
the arrays instead of adding elements one by one.
Added to ArrayMapTests to test new equals() and copy constructor
functionality.
Issue #9299310 Optimize ArrayMap copy constructor
Change-Id: I1186a0eddd1fd53a0f380c2f3972fc1942cdf879
f4130cf35f