Change the 64 bit map address format.

Previously, the map printing in tombstones for 64 bit devices uses
a variable length value. This means that the maps are not lined up.
The new format is to print the map as 00000000'00000000 in all ways.

Also fix a bug where the backtrace_map_t did not initialize all
parameters.

Add unit tests for all of the dump_all_maps function.

Bug: 20950813
Change-Id: I30901c8a0251b00d85c4c01476b033ef8db84e32