move global variable definition out of header

moded a global variable definition of a list of strings out
of a header file and replaced it with an accessor function.

this fixes a compile error regarding multiple definitions of
ecm_tracker_connection_state_to_string and
ecm_tracker_sender_state_to_string encountered when trying to
compile a unified version of ECM.

Change-Id: I42c728b1e42f3f1ecbb9b2561e27430d303f7eaa
Signed-off-by: Nicolas Costa <ncosta@codeaurora.org>
5 files changed