Layoutlib native: make list of classes to register configurable.

Test: frameworks/layoutlib/bridge/tests/run_tests.sh
Test: tools/test/simulated_device/ctesque/run_tests_host.sh
Change-Id: I1b2e13d03b78d085b14adfcf1aa5a8fc19d463cc
(cherry picked from commit 0fca16a8fae9f146a2bc7b6ab1fdb99bb3b7db18)