Additional functionality and performance for ArrayMap

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