Remove do_not_replace_existing_cod_with_uncategorized_cod flag

This flag is now enabled by default and the branch will always return
true.

Bug: 311456944
Bug: 335909751
Flag: EXEMPT, removing fully enabled flag
Test: m com.android.btservices
Change-Id: Ia85b49be0170c04d49221f78692dbb69b2c6264d