Revert accidental removal of PURPOSE_BUGFIX of flag enable_add_app_widget_via_config_activity_v2

ag/26538984 accidentally removes PURPOSE_BUGFIX of enable_add_app_widget_via_config_activity_v2,
this CL will revert that part as a forward fix

Bug: 298089923
Flag: ACONFIG enable_add_app_widget_via_config_activity_v2 TEAMFOOD
Test: just a flag change
Change-Id: I29bbb8c60ae71978ee4129a4751fa4ad0d3706d3
1 file changed