crash_reporter: Fix product_id in kernel crash reports

Move the bdk_version, product_id, and product_version metadata
population into the base crash_collector class so that all
colletors correctly report those fields in crash reports.

BUG=27344416
TEST=crash_reporter_tests passes.

Change-Id: I050053055f197d01661a1442e3cdcccc53c1c8fe