Update the enforce_system_radius_for_app_widgets flag's type

Renamed to use_system_radius_for_app_widgets since metadata cannot be updated after submitting definition.

Bug: 373351337
Test: N/A flag metadata update
Change-Id: I25283b05341517f5984b0f2fc0d27efe8027a3de
Flag: com.android.launcher3.use_system_radius_for_app_widgets