Set flags in RS JNI calls for rsObj creation

Bug: 25570907

Added a flag to all RS runtime API for rsObj creation to indicate a
call is from Java. This flag will help us avoid incrementing the user
ref count for rsObj's created from Single-Source RS, and therefore
avoid memory leaks for such objects.

Change-Id: Id3604f93b166089e3aca896d1c6c509b3ea19bcf
(cherry picked from commit ad880558)